Convert binaries to use pypy

Change-Id: Ifa9e1ac7e9b6d6f1a8071548a42bd1b80b7acb21
Remove test dependency on psycopg2

Psycopg2 doesn't currently work with pypy and it is only needed when
using postgres, so disable it for now.

Change-Id: I7b484615647732d9088762504cb181bf7cec08ce
Remove dependency on websockify

Websockify depends on numpy which is not yet compatible with pypy. Note
that weebsockify is required for novnc proxy so we will have to run
without it for now.

Change-Id: I09e70eec8c3f1052cfd649c770b46fccb6611bef
Hack around lack of support for os.statvfs

Pypy doesn't currently support os.statvfs. Just hack around it for now
by supplying fake values for used and available space.

Change-Id: I61075eeba77a7f5ecee66fa7022e910e47921ea1