Add support for other operating systems besides Redhat/Debian

Prior to this commit, if you attempted to use the module to
manage postgres on any OS other than Redhat/Debian, there
was an explicit check for that, and a call to `fail`.

In reality, the OS family is only used to build up defaults
for various path and package names, which are all exposed
as parameters.  If the user is willing to explicitly pass
in all of those parameters, there's no reason we should
fail based on OS family.

This commit adds checks to the 'default' osfamily case
such that we now only fail if they're on a non-Redhat-or-Debian
system *and* they haven't explicitly passed in values for
all of the required parameters.
Fix up and add some tests for unknown OS patch

This patch just adds some new tests for the unknown OS patch, and cleans up
some existing tests to look for the new warning message.

Also, change the warning message for $osfamily and manage_package_repo to
reflect the parameter at fault.

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #189 from kbarber/feature/master/support-more-distroz

Add more distributions