(MAINT) Update `.travis.yml` with encrypted hipchat credentials.

Also updates `.gitmodules` to enable travis-ci to recursively clone the
repository without ssh credential errors.

Signed-off-by: Wayne <wayne@puppetlabs.com>
Merge pull request #209 from waynr/maint-travisc

(MAINT) Update `.travis.yml` with encrypted hipchat credentials.
(SERVER-18) Added puppet config opts
(SERVER-18) Can use headers for cert CN and auth
(SERVER-18) global config to dissallow cn header

The puppet.conf settings, ssl-client-header and ssl-client-verify-header
are potentially dangerous so an explicit Puppet Server config option was
added. This option is :allow-header-cert-info and it's found in the
global config section.
(SERVER-18) Added tests