restoring 'mock-socket'

Author: leob

package.json

@@ -49,6 +49,7 @@
         "jest": "^24.9.0",
         "jest-websocket-mock": "^2.2.0",
         "laravel-echo": "^1.10.0",
+        "mock-socket": "^9.0.3",
         "rollup": "^2.10.2",
         "rollup-plugin-typescript2": "^0.27.1",
         "standard-version": "^8.0.1",