Remove pin for coveralls

Author: SilkeSchomann

environment.yml

@@ -5,7 +5,7 @@ channels:
   - mantid/label/nightly
 dependencies:
   - coverage
-  - coveralls=3.3.1  # Pinned to a version that works with more recent versions of coverage
+  - coveralls #=3.3.1  # Pinned to a version that works with more recent versions of coverage
   - ipython
   - mock
   - pip