Set dev ruby version to 2.1.2.

I did this so that our development environments are using the latest stable
version of ruby.
Add Ruby 2.1.2 to Travis CI builds plan.

I did this so the code base will be tested against Ruby 2.1.2 as well during
CI.
Upgrade dependency gems.

I did this simply so that we don't fall too far behind.
Changes to allow new language definitions

- Added proper Languages module definition
- added internal storage for languages to Languages
- tests... actually removed some mocking becuse they caused
  false positives
- changed language check of supported_language to use internal storage
  in Languages.
Fixes based on review