Merge pull request #20 from derrh/master

Adds discussion topic implementation
Added params to the course favorites api so it will get the course grade info as well.
Merge pull request #21 from elgreco84/master

Added params to the course favorites api so it will get the course grade...
Added support for Announcements which are basically Discussion Topics
Merge pull request #22 from nlambson/master

Added support for Announcements which are basically Discussion Topics
Header declaration for new Announcements fetch method
Merge pull request #23 from nlambson/master

Header declaration for new Announcements fetch method
Reactivate the client login process
Update sample code to work with the new reactive APIs
Update README.md

update the readme's info on login.
Merge pull request #24 from jarsen/master

Reactive Login + Update Example Project
Add header to load client from keychain.
Merge remote-tracking branch 'instructure/CanvasKit/master'
Merge pull request #25 from jarsen/master

Add header to load client from keychain