$ python sendgrid/helpers/inbound/app.py
Traceback (most recent call last):
  File "sendgrid/helpers/inbound/app.py", line 9, in <module>
    from parse import Parse
  File "/Users/awwa/github/sendgrid-python/sendgrid/helpers/inbound/parse.py", line 5, in <module>
    from six import iteritems
ImportError: No module named 'six'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "sendgrid/helpers/inbound/app.py", line 12, in <module>
    from sendgrid.helpers.inbound.parse import Parse
  File "/Users/awwa/.pyenv/versions/3.5.2/lib/python3.5/site-packages/sendgrid/helpers/inbound/__init__.py", line 2, in <module>
    from .parse import *
  File "/Users/awwa/.pyenv/versions/3.5.2/lib/python3.5/site-packages/sendgrid/helpers/inbound/parse.py", line 5, in <module>
    from six import iteritems
ImportError: No module named 'six'