travis cache pip
travis cache pip

as per

http://docs.travis-ci.com/user/caching/#pip-cache
http://docs.travis-ci.com/user/caching/#Arbitrary-directories

qedsoftware/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq