Added missing backticks (home-assistant#1902)

arsaboo · fabaff · commit 303e2b46ecb6 · 2017-01-30T12:39:56.000+01:00
diff --git a/source/_components/microsoft_face.markdown b/source/_components/microsoft_face.markdown
@@ -82,3 +82,4 @@ After we done with changes on a group, we need train this group to make our AI f
 service: microsoft_face.train_group
 data:
   group: family
+```
