Added short descriptions of the sample Flask LIT Provider project files.
Control flow diagram of how edX works with LTI.
Reference to Flask tutorial.
Modified the Flask control flow diagram
Merge branch 'Feature/Tutorial' of github.mit.edu:mitxlti/mit_lti_flask_sample into Feature/Tutorial
Modified the Flask control flow diagram
Modified Heroku parameters
Merge pull request #9 from mitodl/Feature/Tutorial

Feature/tutorial: These represent the change we discussed in the 12/1/14 sprint planning.  I have reviewed the change and will merge it.