Bump the amount of default forks from 5 to 25, enable pipelining
Bump the amount of default forks from 5 to 25, enable pipelining

Trying to see if it has an impact on performance while still being
a conservative number [1].
We're also speeding up SSH connections by dropping GSSAPIAuthentication.

[1]: http://docs.ansible.com/ansible/intro_configuration.html#forks

Change-Id: Ia21ca8b694253236f5a3f08acf8b53ba2391239a

redhat-openstack/weirdo,rdo-infra/weirdo