Bump etcd version for travist tests.
Bump etcd version for travist tests.

client.update() can work on dirs on write results only if we can know
this was a dir; this is possible only with etcd 0.3.0 or later where
prevNode is available.

jlamillan/python-etcd,sentinelleader/python-etcd,jplana/python-etcd,dmonroy/python-etcd,sentinelleader/python-etcd,vodik/python-etcd,kireal/python-etcd,projectcalico/python-etcd,mbrukman/python-etcd,projectcalico/python-etcd,j-mcnally/python-etcd,dmonroy/python-etcd,vodik/python-etcd,j-mcnally/python-etcd,jlamillan/python-etcd,jplana/python-etcd,ocadotechnology/python-etcd,mbrukman/python-etcd,thepwagner/python-etcd,aziontech/python-etcd,kireal/python-etcd,ocadotechnology/python-etcd,aziontech/python-etcd,thepwagner/python-etcd