Adds Basic Rating Step

Adds the basic rating step react component to display a single step
in the rating widget. Currently hard coded to only display half ratings.

Updates index.js to export the RatingStep component. index.html updated
to render the RatingStep component on the page.
Adds Type Prop to Rating Step to Make Class Dynamic

Uses the type prop to easily allow the user to specific if they want
whole, half, or empty rating steps. Updates example to match.
Adds PropTypes and DefaultProps

Updates RatingStep to only allow a specific values in the type
attribute. All other values now output a console.log warning.

Adds a default value for RatingStep.
Adds RatingWidget Component

Adds the RatingWidget component that wraps multiple RatingStep
components.
Adds Size to RatingWidget

Adds the size prop to RatingWidget to control the number of RatingSteps.
Adds Start of Rating Display

Updates RatingWidget to dynamically set the type of the RatingStep
based on a rating variable.
Adds Support for half ratings

Updates the RatingWidget step to correctly calculate when we need
a half star.
Moves Rating to State and adds Click for Random Rating

Updates RatingWidget to store the rating in its state. Adds an onClick
event to the widget as a whole that randomly sets the rating state to
a number from 1 to the size.
Correctly Sets Rating Based on Step Clicked

Adds step and onClick props to the RatingStep. Clicking on a RatingStep
now calls the onClick props and passes its step property as the first
argument.
Adds an onRate property to RatingWidget

Adds an onRate property to RatingWidget that is called when a rating
is set by clicking on one of the RatingSteps. This allows the
implementer to add a custom callback to respond or save user ratings,
etc.
Adds Support For Detecting Half Rating Clicks

Updates the click handler to be able to detect when a half rating
should be assigned instead of a whole rating. Adds a halfRatings
property to turn on and off half step rating support.

Adds a check to remove the rating if the user attempts to assign the
exact same rating to the widget again.
Add Temporary Rating Support

Updates the Rating Widget to support a temporary rating as the user
hovers over the various rating steps. Adds a property to RatingWidget
to toggle temporary rating support on and off.
Adds Property to Disable Rating Widget

Adds a disable property to RatingWidget and updates the example to
add a disable and enable button.
Adds InitialRating and ClassName Props

Adds an initialRating andd className prop to RatingWidget to allow
for further customization and the ability to assign a rating to the
widget without user interaction.
Adds Better Mobile Device and IE6-8 Support

Updates the rating widget component to not use hover on mobile devices
and to fall back to using images on IE6-8 as these browsers do not
correctly interpert the CSS for the rating steps before and after
z-index trick.