Initial fix for apiEnableAction() and ApiProblem usage
Merge pull request #151 from zfcampus/hotfix/module-enable

Initial fix for apiEnableAction() and ApiProblem usage
[#151] Fix issue with Module entity access

- `injectModuleCollectionRelationalLinks()` was accessing the
  ModuleEntity as if it were an array. Altered to retrieve data from it
  as an array, and then to seed a new ModuleEntity when complete.
[#151] Fix failing unit tests

- Code changed to return an ApiProblemResponse, but the tests were not updated
  to reflect this.
Merge branch 'hotfix/151'

Close #151