Cleanup and fix keychain related code.
Merge remote-tracking branch 'instructure/CanvasKit/master'
Merge pull request #27 from jarsen/master

Cleanup and fix keychain related code.
Added support for Announcements which are basically Discussion Topics
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.
Add header to load client from keychain.
Adds course permissions update endpoint
add fetch by course method for calendar events
Merge pull request #28 from nlambson/master

add fetch by course method for calendar events
Added the path to files and folders. Added some missing properties to files
Merge remote-tracking branch 'instructure/CanvasKit/master'

Conflicts:
	CanvasKit/Networking/CKIClient.m
Merge pull request #29 from elgreco84/master

Files
Add missing path variable for CKICalendarItems
Quickfix for CKICalendarEvent properties that aren't KVO compliant
Merge pull request #30 from nlambson/master

Add missing path variable for CKICalendarItems
Added Assignment Groups endpoint
Merge remote-tracking branch 'instructure/master'