Fixes incomplete tags showing when switching to edit a different post

closes #3065
- send 'reset' action to PostTagsInputController when associated view is destroyed
Merge pull request #3066 from kevinansfield/fix-sticky-incomplete-tags

Fix incomplete tags sticking between post edits
Update Ghost-UI version in bower.json

No issue

- Update the version of Ghost-UI Bower is looking for.
Merge pull request #3090 from PaulAdamDavis/master

Update Ghost-UI version in bower.json
Generate slug when adding new app.

No issue
- Remove duplicate code from model_posts_spec.
- Add slug generation to app model
- Test slug generation on app model