Add all install requirements to setup.py

[AndreasBackx]

In the readme it tells people to install pyyaml and ua-parser alongside this library. ua-parser seems to be included in the setup.py, but pyyaml is not. I'm up to make PR, but I don't know what the minimum required version of pyyaml is. Could you add pyyaml to the setup.py and edit the readme?

[robcowie]

Pretty sure this is solved by 9ad93b8 so this ticket can be closed.

[AndreasBackx]

@robcowie pyyaml still doesn't seem to be added which is why I created this issue. Unless the library no longer needs it?

[robcowie]

Ah I see. I'm pretty sure the readme is wrong. pyyaml isn't a requirement for this library and it's only a requirement for ua-parser during install (it's declared in setup_requires, https://github.com/ua-parser/uap-python/blob/master/setup.py#L186).

Certainly it seems to work in a fresh virtualenv for me without explicitly installing pyyaml. Can you confirm that?