use the current interpreter's pip or easy_install to install python packages

[jstewmon]

fixes #2

[sebasrp]

Please confirm this contribution is under the terms of the MIT license.
Thanks!

[jstewmon]

Hi, this patch is being contributed under the terms of the project's MIT license.

Does awslabs have a corporate CLA? If so (and if you want that assurance), I need to have an officer of my employer sign it.

[hyandell]

No need for a CLA at this time. We'll most likely have you confirm MIT license each time (though that depends on the contribution - large contributions are more likely to involve asking you/your officer to sign something).