Prepare for gating by distro, type, docker type

We will gate on all combos of:
/docker
/docker_templates
Centos
Ubuntu
Binary
Source

Except for Ubuntu + Binary because there is no delorean
style repository for Ubuntu.

Change-Id: Ic1ed8c22c2f86ff339299939da9ac492a7c7c5f5
Partially-Impelements: blueprint gate-source-builds