TEST: Actually test oldest matplotlib

Author: effigies

.travis.yml

@@ -40,7 +40,7 @@ matrix:
     # Absolute minimum dependencies plus oldest MPL
     - python: 2.7
       env:
-        - DEPENDS=numpy==1.5.1 matplotlib==1.3.1 PYDICOM=0
+        - DEPENDS="numpy==1.5.1 matplotlib==1.3.1" PYDICOM=0
     # Minimum pydicom dependency
     - python: 2.7
       env: