Merge pull request #61 from jlpalomino/master

Pin matplotcheck to version 0.0.11

Author: Leah Wasser

environment.yml

@@ -44,6 +44,6 @@ dependencies:
   - jupyter_contrib_nbextensions
   - nbclean
   # Autograding
-  - matplotcheck
+  - matplotcheck=0.0.11
   - nbgrader