specific version of coverage due to issue reported with version 5 of …

…coveralls

.travis.yml

@@ -10,6 +10,7 @@ services:
   - xvfb
 before_install:
 #  - sudo apt-get build-dep python-scipy
+  - pip install coverage==4.5.4  # temporary fix for coveralls
   - pip install coveralls
   - pip install python-coveralls
   - pip install scipy