Update README.md

Added a note about the required Rotten Tomatoes API key.
Added fade-in animation end keyframes for all browsers
Removed validation from login form
Added Google Analytics tracking to pageviews
Nicer looking revenue graph data for sales view
Higher resolution images for schedule view
Updated to Vaadin 7.3.0
Using Ehcache gzip compression
Using Guava's event bus, some refactoring here and there
Various view updates
Did some code refactoring and initial responsive design
Some renamings and removals
Refactoring on various places
More refactoring
Still some refactoring here and there
Changed view packages hierarchy
View updates. Mostly in reports view.
Created a dedicated DashboardNavigator. Transactions get delivered to reports view.
Legends can be scrolled on sales view
Reports view inline text editor to its own class