LearningLocker/learninglocker — pull request #294 by ryansmith94 (2014-08-05 13:11:12+00:00)
Title: Adds empty data points to fix #265.

Zero days are not displayed on the graph. This is a duplicate of @dolfje's pull-request #266 except it merges into the development branch and adds wraps some of the code in an if block in case no dates are provided.