Extended contributing file with better descriptions
Fixed typo
Added requestAnimationFrame polyfill as a bower dev dependency
Added polyfill for requestAnimationFrame on js file
Completely refactored animation function to use `window.requestAnimationFrame` function, fixes #1
Added .travis.yml file
Removed multiplying/dividing of a 100
Added grunt installing for travis test build
Added travis build badge to README file
Added method to extract unit from input start/end values and also tests
Better getUnit method
Adding support to visibleValue prop
Successful implementation of start/visible/end values, fixes #5
Fixed tests
Adding z-index support, relates to #4
Fix initial values
Some fixes on examples and default values
Improving functional tests
Added some rock solid tests and some fixes along the way
Renamed transitionTime property into transitionDuration
Added top/bottom example
Improvements on z-index ordering