Fix package.json keywords.

Previous ones were copy-paste leftovers.

package.json

@@ -12,8 +12,7 @@
     "url": "git+https://lolg.it/herby/deferred-lite.git"
   },
   "keywords": [
-    "redux",
-    "test"
+    "deferred"
   ],
   "author": "Herbert Vojčík <herby@mailbox.sk>",
   "license": "MIT",