title: import sklearn not working in PyCharm
body: <p>I installed numpy, scipy and scikit-learn using pip on mac os. However in PyCharm, all imports work except when i try importing sklearn. I tried doing it in the Python shell and it worked fine. Any ideas as to what is causing this? 
  Also, not sure if it is relevant, but i installed scikit-learn last.</p>
  
  <p>The error I receive is unresolved reference</p>