fix: Add thread safety cop (#17)

feat!: Remove constraints on gems and Travis CI (#15)

* feat!: unconstrain package versions

* fix: travis

* fix: Remove travis

feat: upgrade rubocop to version 1.12.1 (#14)

Version up for new tag (#13)

feat: updated rubocop to version 1.6.x (#11)

* feat: updated rubocop to version 1.6.x

* fix: use right version bump

feat: update rubocop (#10)

fix: update rubocop and removed rubocop-ast pin (#9)

Redmine 2.6