[Tests] use shared travis-ci configs

Author: ljharb

.editorconfig

@@ -30,4 +30,4 @@ max_line_length = off
 max_line_length = off
 
 [.travis.yml]
-indent_size = 2
+indent_size = 1

.travis.yml

@@ -1,38 +1,7 @@
+version: ~> 1.0
 language: node_js
 os:
-  - linux
-node_js:
-  - "10"
-  - "9"
-  - "8"
-  - "7"
-  - "6"
-  - "5"
-  - "4"
-  - "iojs"
-  - "0.12"
-  - "0.10"
-  - "0.8"
-before_install:
-  - 'case "${TRAVIS_NODE_VERSION}" in 0.*) export NPM_CONFIG_STRICT_SSL=false ;; esac'
-  - 'nvm install-latest-npm'
-install:
-  - 'if [ "${TRAVIS_NODE_VERSION}" = "0.6" ] || [ "${TRAVIS_NODE_VERSION}" = "0.9" ]; then nvm install --latest-npm 0.8 && npm install && nvm use "${TRAVIS_NODE_VERSION}"; else npm install; fi;'
-script:
-  - 'if [ -n "${PRETEST-}" ]; then npm run pretest ; fi'
-  - 'if [ -n "${POSTTEST-}" ]; then npm run posttest ; fi'
-  - 'if [ -n "${COVERAGE-}" ]; then npm run coverage ; fi'
-  - 'if [ -n "${TEST-}" ]; then npm run tests-only ; fi'
-sudo: false
-env:
-  - TEST=true
-matrix:
-  fast_finish: true
-  include:
-    - node_js: "lts/*"
-      env: PRETEST=true
-  allow_failures:
-    - node_js: "9"
-    - node_js: "7"
-    - node_js: "5"
-    - node_js: "iojs"
+ - linux
+import:
+ - ljharb/travis-ci:node/all.yml
+ - ljharb/travis-ci:node/pretest.yml