Current dependencies (and Travis build) don't work with PHP 7.0 & 7.1

[sampart]

You can see that in this Travis build: https://travis-ci.org/whiteoctober/Pagerfanta/builds/262136555

In case that URL stops working, here's the lengthy relevant extract. Notice both the failure to load PHP extensions and the failure to install dependencies:

$ composer install
PHP Warning:  PHP Startup: Unable to load dynamic library '/home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so' - /home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so' - /home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so: cannot open shared object file: No such file or directory in Unknown on line 0
PHP Warning:  PHP Startup: Unable to load dynamic library '/home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so' - /home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so: cannot open shared object file: No such file or directory in Unknown on line 0
Warning: PHP Startup: Unable to load dynamic library '/home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so' - /home/travis/.phpenv/versions/7.1.7/lib/php/extensions/no-debug-zts-20160303/mongo.so: cannot open shared object file: No such file or directory in Unknown on line 0
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.
  Problem 1
    - doctrine/mongodb-odm 1.0.0-BETA6 requires doctrine/mongodb >=1.0.0-beta1,<1.1-dev -> satisfiable by doctrine/mongodb[1.0.0, 1.0.1, 1.0.10, 1.0.11, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.9].
    - doctrine/mongodb-odm 1.0.0-BETA7 requires doctrine/mongodb 1.0.* -> satisfiable by doctrine/mongodb[1.0.0, 1.0.1, 1.0.10, 1.0.11, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.9].
    - doctrine/mongodb-odm 1.0.0-BETA8 requires doctrine/mongodb 1.0.* -> satisfiable by doctrine/mongodb[1.0.0, 1.0.1, 1.0.10, 1.0.11, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.9].
    - doctrine/mongodb-odm 1.0.0-BETA9 requires doctrine/mongodb 1.0.* -> satisfiable by doctrine/mongodb[1.0.0, 1.0.1, 1.0.10, 1.0.11, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.9].
    - doctrine/mongodb-odm 1.0.0-BETA10 requires doctrine/mongodb >=1.1.5,<2.0 -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.0-BETA11 requires doctrine/mongodb >=1.1.5,<2.0 -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.0-BETA12 requires doctrine/mongodb >=1.1.5,<2.0 -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.0-BETA13 requires doctrine/mongodb >=1.1.5,<2.0 -> satisfiable by doctrine/mongodb[1.1.5, 1.1.6, 1.1.7, 1.1.8, 1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.2.x-dev requires doctrine/mongodb ^1.4.0 -> satisfiable by doctrine/mongodb[1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.0 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.1 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.2 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.3 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.4 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.5 requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.1.x-dev requires doctrine/mongodb ~1.3 -> satisfiable by doctrine/mongodb[1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.0 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.1 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.2 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.3 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.4 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.5 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.6 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.7 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.8 requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb-odm 1.0.x-dev requires doctrine/mongodb ~1.2 -> satisfiable by doctrine/mongodb[1.2.0, 1.2.1, 1.2.2, 1.3.0, 1.4.0, 1.5.0].
    - doctrine/mongodb 1.0.9 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.8 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.7 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.6 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.5 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.4 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.3 requires ext-mongo >=1.2.12,<1.5-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.2 requires ext-mongo >=1.2.12,<1.4-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.11 requires ext-mongo >=1.2.12,<1.7-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.10 requires ext-mongo >=1.2.12,<1.7-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.1 requires ext-mongo >=1.2.12,<1.4-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.0.0 requires ext-mongo >=1.2.12,<1.4-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb-odm 1.0.0-BETA5 requires doctrine/mongodb 1.0.0-BETA1 -> satisfiable by doctrine/mongodb[1.0.0-BETA1] but these conflict with your requirements or minimum-stability.
    - doctrine/mongodb-odm 1.0.0-BETA4 requires doctrine/mongodb 1.0.0-BETA1 -> satisfiable by doctrine/mongodb[1.0.0-BETA1] but these conflict with your requirements or minimum-stability.
    - doctrine/mongodb 1.1.8 requires ext-mongo >=1.2.12,<1.7-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.1.7 requires ext-mongo >=1.2.12,<1.7-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.1.6 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.1.5 requires ext-mongo >=1.2.12,<1.6-dev -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.5.0 requires ext-mongo ^1.5 -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.4.0 requires ext-mongo ^1.5 -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.3.0 requires ext-mongo ^1.5 -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.2.2 requires ext-mongo ^1.2.12 -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.2.1 requires ext-mongo ^1.2.12 -> the requested PHP extension mongo is missing from your system.
    - doctrine/mongodb 1.2.0 requires ext-mongo ^1.2.12 -> the requested PHP extension mongo is missing from your system.
    - Installation request for doctrine/mongodb-odm ~1.0@dev -> satisfiable by doctrine/mongodb-odm[1.0.0, 1.0.0-BETA10, 1.0.0-BETA11, 1.0.0-BETA12, 1.0.0-BETA13, 1.0.0-BETA4, 1.0.0-BETA5, 1.0.0-BETA6, 1.0.0-BETA7, 1.0.0-BETA8, 1.0.0-BETA9, 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.0.5, 1.0.6, 1.0.7, 1.0.8, 1.0.x-dev, 1.1.0, 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5, 1.1.x-dev, 1.2.x-dev].
  To enable extensions, verify that they are enabled in your .ini files:
    - /home/travis/.phpenv/versions/7.1.7/etc/php.ini
    - /home/travis/.phpenv/versions/7.1.7/etc/conf.d/travis.ini
    - /home/travis/.phpenv/versions/7.1.7/etc/conf.d/xdebug.ini
  You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.
The command "composer install" failed and exited with 2 during .
Your build has been stopped.