Update change log for 0.2.0
Update change log for 0.2.0

Change-Id: Id87cffa0938c7cd203d91b91be85a13ee4e4afd4

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