bump polkadot api

package.json

@@ -21,8 +21,8 @@
     "build:js": "babel src/ --extensions '.ts,.js' --out-dir dist/"
   },
   "dependencies": {
-    "@polkadot/api": "^6.5.2",
-    "@polkadot/util-crypto": "^7.7.1",
+    "@polkadot/api": "^6.11.1",
+    "@polkadot/util-crypto": "^8.1.2",
     "probot": "^11.0.1"
   },
   "devDependencies": {