Simplify testing setup
Simplify testing setup

- removed iojs - just use node
- separated scss_lint and js_tests
- removed ember-beta and canary tests
- retry sauce connect when it fails

dartajax/frontend,ilios/frontend,gabycampagna/frontend,jrjohnson/frontend,thecoolestguy/frontend,stopfstedt/frontend,djvoa12/frontend,gboushey/frontend,thecoolestguy/frontend,jrjohnson/frontend,dartajax/frontend,gabycampagna/frontend,stopfstedt/frontend,ilios/frontend,djvoa12/frontend,gboushey/frontend