title: pycharm generates wrong target path for tests
body: <p>using Pycharm 2017.1.3 (but saw it in other versions as well) - 
  When running single test (right click the test and run), the test target configuration that automatically created is wrong - before the class name it puts dot (.) instead of colon(:), so it looks like it's a function. For that reason, when running the single test, I'm getting this error:</p>
  
  <pre><code>Traceback (most recent call last):
  File "/Users/...../python3.6/site- 
  packages/nose/failure.py", line 39, in runTest
  raise self.exc_val.with_traceback(self.tb)
  File "/Users/...../python3.6/site- 
  packages/nose/loader.py", line 523, in makeTest
  return self._makeTest(obj, parent)
  File "/Users/...../python3.6/site- 
  packages/nose/loader.py", line 576, in _makeTest
  if issubclass(parent, unittest.TestCase):
  TypeError: issubclass() arg 1 must be a class
  </code></pre>
  
  <p>for example, this target:</p>
  
  <pre><code>myproject.utils.tests.test_integration.MyNewService.test_use_case
  </code></pre>
  
  <p>should be:</p>
  
  <pre><code>myproject.utils.tests.test_integration:MyNewService.test_use_case
  </code></pre>