Install python-magic package on setup

[ilyaglow]

Hey guys,

I noticed that installing thehive4py from PyPI doesn't let you use the client, because python-magic package is missing in the setup.py. The error message I receive is:

...
    from thehive4py.api import TheHiveApi
  File "/home/ilya/thehive-env/lib/python3.5/site-packages/thehive4py/api.py", line 8, in <module>
    import magic
ImportError: No module named 'magic'

Same for python 2.7:

...
    from thehive4py.api import TheHiveApi
  File "/home/ilya/.local/share/virtualenvs/thehive-LPUGdsMD/local/lib/python2.7/site-packages/thehive4py/api.py", line 8, in <module>
    import magic
ImportError: No module named magic

This PR should resolve the issue.

[nadouani]

Well, I think we misunderstood the difference between setup.py and requirements.txt. I'll merge this PR, Thanks

For reference: https://caremad.io/posts/2013/07/setup-vs-requirement/

[nadouani]

This will be be included on the next release.