Create group via webservices also creates group category if not existing

[Robert Lyon]

Currently when one creates a group via webservices they can pass in a group category and if the category exists in Mahara the group is made.

But if the group category does not exist then webservices throws an error

As it's pretty safe to create missing group categories we should just make it if missing

[Mahara Bot (dev-mahara)]

Patch for "master" branch: https://reviews.mahara.org/7941

[Mahara Bot (dev-mahara)]

Reviewed: https://reviews.mahara.org/7941
Committed: https://git.mahara.org/mahara/mahara/commit/1238d0eab123878ddfeb257838bd1447d65c3f63
Submitter: Robert Lyon (<email address hidden>)
Branch: master

commit 1238d0eab123878ddfeb257838bd1447d65c3f63
Author: Robert Lyon <email address hidden>
Date: Wed Aug 23 13:08:25 2017 +1200

Bug 1712454: Allow webservices create group category

If it doesn't already exist in Mahara and we pass in the
'forcecategory' parameter with value '1' for true

behatnotneeded

Change-Id: Ic5c7023262b9683153463940139ae8c22645eba8
Signed-off-by: Robert Lyon <email address hidden>