Fix teuthology installations on physical Centos machines.
Yum installs of packages specify a pacakge number.  Initial
install of yum source changed to not fail if already done.
Added yum cleans where necessary.

Fixes: #4768
Signed-off-by: Warren Usui <warren.usui@inktank.com>
ceph_manager: add timeout option to revive, increase for power_cycle

Signed-off-by: Samuel Just <sam.just@inktank.com>
install: default to ceph project throughout

Signed-off-by: Sage Weil <sage@inktank.com>
Merge branch 'wip-teuth4768a-wusui'

Conflicts:
	teuthology/task/install.py