recently a docker integration plugin was merged, which requires docker
python bindings.
to fix your env dependencies just add it:
yum install python-docker-py
wiki[1] updated accordingly and a patch[2] for README.developer is on
the way
[1]
http://www.ovirt.org/OVirt_Engine_Development_Environment#Install_3rd_par...
[2]
https://gerrit.ovirt.org/#/c/40532/