title: Pip can't install flask-socketio
body: <p>I want to install the module flask-socketio using pip2, however I get an error, that no matching bidict version was found. I looked bidict up, and it turns out,  that the version doesnt even exist. I tried installing some other packets, but nothing worked. Here you can see the full error</p>
  <p>'''
  ERROR: Could not find a version that satisfies the requirement bidict&gt;=0.21.0 (from python-socketio&gt;=5.0.2-&gt;flask-socketio) (from versions: 0.1.5, 0.2.1, 0.3.0, 0.3.1, 0.9.0rc0, 0.9.0.post1, 0.10.0, 0.10.0.post1, 0.11.0, 0.12.0.post1, 0.13.0, 0.13.1, 0.14.0, 0.14.1, 0.14.2, 0.15.0.dev0, 0.15.0.dev1, 0.15.0rc1, 0.15.0, 0.16.0, 0.17.0, 0.17.1, 0.17.2, 0.17.3, 0.17.4, 0.17.5, 0.18.0, 0.18.1, 0.18.2, 0.18.3, 0.18.4)
  ERROR: No matching distribution found for bidict&gt;=0.21.0 (from python-socketio&gt;=5.0.2-&gt;flask-socketio)
  '''</p>
  <p>Any Ideas?</p>