title: Gurobi optimizer on python
body: <p>I need a free optimizer for python. I use PYCharm and python 3.6 (I have python 2.7 on my lap top too)
  Now, want to install Gurobi optimizer in PYCharm. but there are some problems: 
  when I wanted to install "gurobipy" library, the first error was on pip version. It was 9.0.3 and I had to upgrade that to 10.0.1. I've done that successfully and now when I want to install gurobipy, its error again: (AttributeError: module 'pip' has no attribute 'main')
  After a quick search, I found that this is a problem of pip 10.0.1
  And now I'm really confused. Can anyone help me? I really need this optimizer on python</p>