Run all-in-one instead of sahara-api

We're upgrading sahara architecture, so, we've added an alias to run
sahara in all-in-one process.

Change-Id: I7f92e13c1a9b15070c5ec46428ca3949190abfc9
Merge "Run all-in-one instead of sahara-api"
Merge branch 'master' of github.com:openstack-dev/devstack