function createFirebaseStub(otherConfig = {}, extensions) {
  return {
    _: {
      uid,
      config: {
        userProfile: 'users',
        ...otherConfig
      }
    },
    auth: createAuthStub(),
    database: createRtdbStub(extensions && extensions.database),
    firestore: createFirestoreStub(),
    storage: createStorageStub()
  }
}
@param extensions
@param {object} otherConfig - Config to be spread onto _.config object
@param rtdbRefExtension
@returns {object} Stubbed version of Firebase JS SDK extended with
react-redux-firebase config