fix(e2e): fix travis webdriver issue (#266)

.travis.yml

@@ -16,5 +16,5 @@ install:
   - npm install
 script:
   - npm run lint
-  - npm run test-once 
+  - npm run test-once
   - npm run e2e

package.json

@@ -59,7 +59,8 @@
     "karma-htmlfile-reporter": "^0.3.4",
     "karma-jasmine": "^1.0.2",
     "karma-jasmine-html-reporter": "^0.2.2",
-    "protractor": "^4.0.9",
+    "protractor": "4.0.9",
+    "webdriver-manager": "10.2.5",
     "rimraf": "^2.5.4",
 
     "@types/core-js": "^0.9.34",