Merge branch 'release/0.5.0' into develop
README.md minor update.
Minor fix.
Merge branch 'develop' of https://github.com/trema/paper-house into develop
Update gem dependencies.
Fix rake portability task.
Refactor Rakefile.
Use guard-bundler 2.0.0.
Delete unnecessary coveralls setups.
Merge pull request #8 from trema/feature/travis_refactoring

Delete unnecessary coveralls setups.
Updated bundled gems.
Merge pull request #9 from trema/feature/update_bundles

Updated bundled gems.
Raise BuildFailed if cc command execution fails
Merge pull request #11 from trema/feature/buildfailed

Raise BuildFailed if cc command execution fails
Upgrade rubocop.
Move testing gems to :test group.
Fix travis error.
Add cucumber and aruba to test group.
Add 2.1 and ruby-head to Travis target.
Update bundled gems.