IDM-1274: Add unit test for validateUid.
IDM-1274: In Groovy everything is a String.
IDM-1274: Remove reduntant null check.
IDM-1274: Check that the uid only contains alphanumeric chars.
IDM-1274: Do length check with regex, for consistency.
IDM-1274: Raise limit to 10 chars.
Merge pull request #106 from janj-su/IDM-1274

IDM-1274: There are uid:s that are atleast 10 chars long in SUKAT.