title: virtualenv doesnt find installed module when running tests [Pytest]
body: <p>I'm writing my first test for a class where I imported an external packages ( installed via pip in the venv ).
  I'm using PyCharm as an IDE and it the package in question is listed there under the project interpreter ( the venv ) as well as when I type <code>pip freeze</code> in console.
  Now I want to <code>run</code> a <code>run-tests.sh</code> file and when my test is reached <code>pytest</code> is returning me an <code>ERROR</code> : <code>E ImportError: No module named 'magic'</code></p>
  
  <p>The code line which fails the test is obviously the import statement in my class which I want to test.</p>
  
  <p>Any ideas?</p>
  
  <p>//Edit: 
  <em>for clarification:</em> <strong>NOT the terminal itself is throwing the Error! <code>PYTEST</code> does!</strong></p>