Revert "Use shared Travis CI configs"
Revert "Use shared Travis CI configs"

This reverts commit f2e7589fad225c51d8229863db8b03da8f943d08.

Our shared config installs newest RubyGems which vendors Bundler 2.1.2
which is not possible to uninstall.

twingly/twingly-url_cache,twingly/twingly-url_cache