Bump version to v0.5.2.
Bump version to v0.5.2.

defunkt/fakefs,onehub/fakefs,deployable/fakefs,1234-/fakefs,vhl/fakefs,dekz/fakefs,marxarelli/fakefs,anthonyryan1/fakefs,pivotal-cf-experimental/fakefs,fakefs/fakefs,bquorning/fakefs