[#82988170] Admin DOI interface matches mocks
[#82988170] Prevent editing of starting number
Merge remote-tracking branch 'origin/master' into doi_ui

Conflicts:
	app/assets/javascripts/templates/journal/index.hbs
Do not validate if the field is empty
[#82988170] renamed doi start variable in ember
[#82988170] fix specs and some markup
Upgrade to Ruby 2.1.5
Allow source to be a changeable computed property
Replace chosen with Select2 on contributors overlay
create new doi in a trasaction
Merge pull request #641 from Tahi-project/paper_doi

create new doi within a trasaction
Fix spec
Merge pull request #642 from Tahi-project/select2_on_add_collaborators

Select2 on add collaborators
Merge pull request #624 from Tahi-project/doi_ui

DOI UI
Rename specs to remove MessageTask dependency

Is there a need to keep both the feature spec and the Ember integration
spec?
remove spring
Remove duplicate method
MessageTask be gone
Add migration:
 - Changes MessageTasks to AdHocTasks
 - Removes MessageTask as an option to create tasks/task-templates
re-remove author groups and message participants from schema