Fix CI again caused by Bundler v2 (#120)

* Remove broken bundler uninstall from CI

* Only build direct pushes to master branch

This makes CI only run builds for pull requests, not pushes

Author: valscion

.travis.yml

@@ -1,4 +1,7 @@
 language: ruby
+branches:
+  only:
+    - master
 rvm:
   - 2.3
 gemfile:
@@ -11,7 +14,6 @@ gemfile:
   - gemfiles/rails_5_1_pundit_2.gemfile
   - gemfiles/rails_5_2_pundit_2.gemfile
 before_install:
-  - rvm @global do gem uninstall bundler -a -x
   - gem install bundler -v '< 2'
 notifications:
   email: false