title: Common convention for invoking unit tests across a python project?
body: <p>Is there a standard convention, or even a growing one, around where and how to invoke the tests associated with a project? In many projects, I'm seeing it bundled into a Make, a separate test.py script at the top level of the project, etc to do the work. </p>
  
  <p>I looked around for some common thing with setup.py, but didn't spot anything there (granted, I didn't look hard). What's common and best practice?</p>