Fixes #7233 - Drop Ruby 1.8.7 and revert Ruby 1.8.7 specifics

- [x] rake test passed
- [x] rails server loaded and function correctly
- [x] Ubuntu 12.04 packaging blocker issue 
- [x] drop 1.8.7 tests on Jenkins
I can't reproduce this with ruby2ruby 2.1.3, ruby_parser 3.6.3 when previewing templates.