fix a trivial type: need "_test"

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/trac352@3138 e5f2f494-b856-4b98-b285-d166d9295462

src/lib/python/isc/utils/tests/Makefile.am

@@ -1,4 +1,4 @@
-PYTESTS = process_test.py serve_mixin.py
+PYTESTS = process_test.py serve_mixin_test.py
 EXTRA_DIST = $(PYTESTS)
 
 # later will have configure option to choose this, like: coverage run --branch