ImportError: No module named yaml

[ndbroadbent]

I got the following error when running ./rigger provision:

Traceback (most recent call last):
  File "/Users/ndbroadbent/.rigger/105216290f/go/src/github.com/deis/deis/contrib/aws/gen-json.py", line 6, in <module>
    import yaml
ImportError: No module named yaml

It was fixed by running pip install pyyaml. Could this be added as a dependency?