Upgrade pyflakes to 0.8.1
Upgrade pyflakes to 0.8.1

Change-Id: I54f50a0133d13329698dae5812cb4343d3f2f221

sonyxperiadev/pygerrit,benjiii/pygerrit,gferon/pygerrit2,dpursehouse/pygerrit,markon/pygerrit2,dpursehouse/pygerrit2