Fix end-to-end tests failing on Travis CI

package.json

@@ -149,7 +149,7 @@
     "test": "standard && karma start karma.conf.js && nyc --report-dir=./build/reports/coverage/server-tests mocha test/server",
     "frisby": "nyc --report-dir=./build/reports/coverage/api-tests node ./test/apiTests.js",
     "preupdate-webdriver": "npm install",
-    "update-webdriver": "webdriver-manager update",
+    "update-webdriver": "webdriver-manager update --gecko false",
     "preprotractor": "npm run update-webdriver",
     "protractor": "node test/e2eTests.js",
     "stryker": "stryker run stryker.client-conf.js",