Proposal to add integration jobs as downstream of the push job

As the integration jobs currently rebuild their own server, their is no need
to wait until completion of the build jobs to trigger them.
Merge pull request #735 from sbesson/integration_graph

Proposal to add integration jobs as downstream of the push job
rebase 712
Merge pull request #739 from hflynn/rebased/develop/icehome

Unix/Linux installation: Update requirements (rebased onto develop)