Add pytest-cov

Add fix for coverage

Add source and omit to coveragerc

Update coveragerc

Update coveragerc

Add source to coveragerc

Update coveragerc source

Add init to tests

Fix ImportError

Fix ImportError again

.coveragerc

@@ -1,6 +1,2 @@
 [run]
-branch = True
-source = camelot
-include = */camelot/*	
-omit =
-    */setup.py
+branch = True