Try to remove libssl for linux build

Author: mschenk42

.travis.yml

@@ -12,6 +12,7 @@ before_install:
   - cd $GOPATH/src/github.com/git-time-metric/git2go
   - git checkout next
   - git submodule update --init
+  - sudo apt-get remove libssl-dev || true
   - make install
   - cd $TRAVIS_BUILD_DIR