removed sign in from the Angular app :scissors:

so since the sign in is going to be handled by rails directly I got
rid of the views/links of sign in from the Angular app
changed colors basically, not much to explain
more style changes, I think the sidebar stays this way now
started implementing notifications

On the new course form I've started adding notifications to handle
the events of success and error, still some polishing to do.
Working towards #28
added more feedback to the UI, basics finished :godmode:

this commit should close #28, added pace.js and notification
messages for every action. Maybe in the future I could block the
button while the action is being performed, but for now it does what
I want it to do.
Merge pull request #35 from rcsole/user-feedback

User feedback