Add PyPi badges
Add PyPi badges

PyPi supports super cool badges in the README. They can show
latest version, # of downloads, docs, CI, code coverage, etc.

Change-Id: I2686e98fb8e047af4a587ebc0eeb7a09a3a0fe3d

stackforge/bandit,stackforge/bandit,pombredanne/bandit,pombredanne/bandit,chair6/bandit