Merge pull request #54 from ss23/0.6

MINOR Clarify dependency on CMS

composer.json

@@ -18,9 +18,10 @@
 		"silverstripe/framework": "3.*,<3.2",
 		"composer/installers": "*",
 		"silverstripe/messagequeue": "*",
-		"silverstripe/gridfieldajaxrefresh": "*"
+		"silverstripe/gridfieldajaxrefresh": "*",
+		"silverstripe/cms": "3.*"
 	},
 	"autoload": {
 		"classmap": ["tests/behat/"]
 	}
-}
\ No newline at end of file
+}