Add a space between super's and setUpClass

When sub class calls BaseTestCase's setUpClass, the error message
reads "RuntimeError: setUpClass does not calls the
super'ssetUpClass in the xxx". super'ssetUpClass should be
super's setUpClass.

Change-Id: I9f9157da443e558652981c2d29580846b8e786f4
Closes-bug: 1618735
1 file changed