chore(): update the EventSource version

- from 1.0.3 to 1.0.4
- there was an issue with a gitsubmodule of the EventSource pointing to a wiki page that messes up the npm package if you don't have ssh GitHub credentials

Author: ctranxuan

package.json

@@ -67,6 +67,6 @@
   "dependencies": {
     "core-js": "^2.4.1",
     "eventsource": "streamdataio/eventsource-js.git#v1.0.6",
-    "eventsource-polyfill": "streamdataio/EventSource.git#v1.0.3"
+    "eventsource-polyfill": "streamdataio/EventSource.git#v1.0.4"
   }
 }