tests: skip test-censor.t when using simple store

Censor assumes the use of revlogs.

Proper censor support for non-revlog storage will require a better
abstraction in the storage layer to remove data. Let's skip the
censor tests until we have something in place.

Differential Revision: https://phab.mercurial-scm.org/D3090

tests/test-censor.t

@@ -1,3 +1,5 b''
+#require no-reposimplestore
+
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > censor=