[HOTFIX] [ZEPPELIN-1863] Travis Selenium CI fail

[soralee]

What is this PR for?

Currently, the Selenium CI test of Travis regarding every PR is failing.
I think because it is after merging #1777 PR.

Here is error log.

Caused by: org.openqa.selenium.NoSuchElementException: Unable to locate element: {"method":"xpath","selector":"(//div[@ng-controller=\"ParagraphCtrl\"])[2]//div[@class=\"control ng-scope\"]//ul[@class=\"dropdown-menu\"]/li[1]"}


Results :
Tests in error: 
  ZeppelinIT.testAngularRunParagraph:291 » NoSuchElement Unable to locate elemen...

What type of PR is it?

[Bug Fix | Hot Fix]

Todos

• fix code regarding this problem

What is the Jira issue?

https://issues.apache.org/jira/browse/ZEPPELIN-1863

How should this be tested?

• None

Screenshots (if appropriate)

• None

Questions:

• Does the licenses files need update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No

[AhyoungRyu]

@soralee CI is green now. Thanks for the quick fix!
Merge into master as a hotfix.