Update gems

Particularly, update gmaps4rails to v2.0.
Remove hard limit for citation length
Truncate note text after --30-- or similar
Update gems
Exclude local urls from Link
Update gems

New paper_trail version is not recognising temporary versioning.
Versioning is now turned on at all times, which is sub-optimal.
Promote notes tagged with '__PROMOTE' in footer and home page
Refactor populate method

Reduce complexity.
Merge remote-tracking branch 'upstream/staging' into staging

Conflicts:
	Gemfile.lock
	app/views/application/_footer.html.slim
	config/compass.rb
	spec/vcr_cassettes/feature.yml