travis config update

.travis.yml

@@ -23,7 +23,7 @@ install:
   - "pip install ."
 # command to run tests, e.g. python setup.py test
 script:  
-  coverage run --source=pwman setup.py test
+  {envpython} setup.py develop && coverage run --source=pwman setup.py test
     
 after_success:
   coveralls