Add ability to set time zone

In Grizzly releases we had an option in site.pp to allow users
to specify the time zone they were in.  This commit adds
a hiera lookup for the time_zone option and passes it on to
the cobbler manifests accordingly.

Partial-Bug: #1263310
Add ability to set time zone

In Grizzly releases we had an option in site.pp to allow users
to specify the time zone they were in.  This commit adds
a hiera lookup for the time_zone option and passes it on to
the cobbler manifests accordingly.

Partial-Bug: #1263310
Merge branch 'bugs/1263310_timezone' of https://github.com/CiscoSystems/puppet-coi into bugs/1263310_timezone

Conflicts:
	manifests/profiles/cobbler_server.pp
Merge pull request #33 from CiscoSystems/bugs/1263310_timezone

Add ability to set time zone