Replace deprecated licenses key with the new format in package.json

Author: dekelev

package.json

@@ -11,12 +11,7 @@
     "objection",
     "orm"
   ],
-  "licenses": [
-    {
-      "type": "MIT",
-      "url": "https://github.com/mcchrish/feathers-objection/blob/master/LICENSE"
-    }
-  ],
+  "license": "MIT",
   "repository": {
     "type": "git",
     "url": "git://github.com/mcchrish/feathers-objection.git"