add compose test descriptions

adding compose test descriptions and validations.

Signed-off-by: baude <bbaude@redhat.com>

test/compose/simple_port_map/README.md

@@ -0,0 +1,9 @@
+simple port map to host
+===============
+
+This test creates a container that runs flask on and maps to the same
+host port
+
+Validation
+------------
+* curl http://localhost:5000 and verify message