Update the distribute dependency version.
Update the distribute dependency version.

MySQL-python requires the version of distribute to be >=0.6.28.

Change-Id: I44f77481208e1c3d6babd3b7d259f4a450a898c8

faizan-barmawer/ironic-lib,NaohiroTamura/ironic-lib,citrix-openstack-build/ironic-lib,faizan-barmawer/elytics,openstack/ironic-lib