v1.4.0

Notable Changes

• removed underscore.js in favor of manual string interpolation and Array.forEach
• updated to support grunt 1.4.x

Chores

• reworked test runner to leverage fixture Gruntfiles for the two scenarios under test

Update datauri dep

Updates datauri to latest (0.5.5)

Adds ability to generate variables into a SassMap

As per @tylerball: "I'd like to be able to push the variables into a map so I can iterate through the icons easily. For example generating icon-name classes for all the icons in a given task target."