Change error message response

closes #2643
- added error type
- added error property for validations
- wrapped errors in an array
- returns multiple errors for validation
- updated tests and admin
Merge pull request #2669 from sebgie/issue#2643

Change error message response
updated error handling on all mocha tests

- switch to using catch
- added error handling where missing
Merge pull request #2692 from cobbspur/newerror

updated error handling on all mocha tests
Docs: switch to docker & finalise config

 - We no longer need grunt-groc as we are going to use docker instead
 - Compile docker to 'docs'
 - Docker has a nice option for only building updated files
 - Added a few files we didn't need dockering to exclude list