ss4upgrade: Updated composer file

Author: adunn

composer.json

@@ -8,7 +8,11 @@
 		"issues": "http://github.com/Copperis/DropdownImageField/issues"
 	},
 	"require": {
-		"silverstripe/framework": "~3.1",
-		"silverstripe/cms": "~3.1"
-	}
+		"silverstripe/framework": "^4.3",
+		"silverstripe/cms": "^4.3"
+	},
+    "expose": [
+        "css",
+        "javascript"
+    ]
 }