Bump deps (#861)

* Bump deps

* Align with published common

* Fix rxjs to 6.4.0 (false deprecations on 6.5.1)

packages/rpc-core/package.json

@@ -29,10 +29,10 @@
   },
   "homepage": "https://github.com/polkadot-js/api/tree/master/packages/rpc-core#readme",
   "dependencies": {
-    "@babel/runtime": "^7.4.3",
+    "@babel/runtime": "^7.4.4",
     "@polkadot/jsonrpc": "^0.78.0-beta.0",
     "@polkadot/rpc-provider": "^0.78.0-beta.0",
     "@polkadot/types": "^0.78.0-beta.0",
-    "@polkadot/util": "^0.76.1"
+    "@polkadot/util": "^0.90.0-beta.1"
   }
 }