ss4upgrade: fixed template and requirements issues

Author: adunn

composer.json

@@ -8,8 +8,8 @@
 		"issues": "http://github.com/Copperis/DropdownImageField/issues"
 	},
 	"require": {
-		"silverstripe/framework": "^4.3",
-		"silverstripe/cms": "^4.3"
+		"silverstripe/framework": "^4",
+		"silverstripe/cms": "^4"
 	},
     "expose": [
         "css",