Remove trust policy recommendation [ci skip]
Test against Rubinius 2
Test against JRuby in additional modes
Test against Ruby 2.1.0
Test against ruby-head
Add temporary workaround for failing build on Ruby 1.8.7

Rubygems broke builds on Ruby 1.8.7:

https://github.com/travis-ci/travis-ci/issues/1793
https://github.com/rubygems/rubygems/pull/763

This patch is a temporary workaround until rubygems is updated.
Lock mime-types to ~> 1.25 on Ruby 1.8 and JRuby in 1.8-mode
Update multi_json dependency to ~> 1.3
Update jwt dependency to ~> 0.1.8
`be_true` is deprecated

Use `be true` (for exact `== true` equality) instead.
`be_false` is deprecated

Use `be false` (for exact `== false` equality) instead.
Enforce code coverage minimums
Add RuboCop
Fix RuboCop offenses
Fix tests on Rubinius
Add Yardstick
Warnings check is performed by RuboCop
Remove non-existant JRuby modes
Update EndAlignment and CaseIndentation style [ci skip]
Fail slow