engine: Require less ram to build

… and split build time CPU+RAM from runtime CPU+RAM.

Change-Id: I2a4e5a6c003bab12e062b47d518b2d60d26ca64f
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>
engine: Compensate upstream cloud image changes

Change-Id: I549db8eb5b76853a5e353906b4d2eea050c1ad5b
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>