(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.