[#83673882] Fixed image links
Merge pull request #119 from 18F/no-travis

remove references to Travis
use roadie-rails instead of roadie
upgrade gems
go back to fetching omniauth-myusa over https
use rails asset url helpers for images
Merge remote-tracking branch 'origin/master' into 83673882_fix_logo_links
use url helpers for image tags
use url helper for stylesheet in communicart_base helper
Merge pull request #122 from 18F/83673882_fix_logo_links

[#83673882] fix logo links
Merge pull request #120 from 18F/upgrade-roadie

upgrade gems
Revert to roadie gem for email css inline style conversion
Merge pull request #123 from 18F/railroady_revert

Revert to roadie gem for email css inline style conversion
upgrade to roadie-rails