Changed Application Layout to use Slim template

We used a gem called erb2slim to do the conversion.

Closes https://github.com/rapidftr/tracker/issues/130
Merge pull request #659 from RapidRailsGirls/erb2slim

Merged, Thanks!
Merge branch 'master' of github.com:rapidftr/RapidFTR

Conflicts:
	Gemfile.lock
	app/views/layouts/application.html.erb