Add maintenance page

This page will be used for times when rubeque is unavailable.
Merge branch 'develop'
Fix merge conflicts
Update maintenance page per heroku customization docs
Merge branch 'develop'
Update maintenance page to use trackman addon
Fix conflict in Gemfile.lock
Merge branch 'master' of github.com:SciMed/rubeque

Conflicts:
	features/submit_solutions.feature