Add: UI test script to Travis

[vibhorgupta-gh]

Addresses #740 partially

Make sure these boxes are checked before your pull request (PR) is ready to be reviewed and merged. Thanks!

• tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR -- or run tests locally with npm test
• code is in uniquely-named feature branch and has no merge conflicts
• PR is descriptively titled
• ask @publiclab/reviewers and @publiclab/is-reviewers for help, in a comment below

We're happy to help you get this ready -- don't be afraid to ask for help, and don't be discouraged if your tests fail at first!

If tests do fail, click on the red X to learn why by reading the logs.

Please be sure you've reviewed our contribution guidelines at https://publiclab.org/contributing-to-public-lab-software

Thanks!

[vibhorgupta-gh]

@publiclab/is-reviewers @publiclab/reviewers

[dojutsu-user]

Codecov badge from README is missing.

[dojutsu-user]

@VibhorCodecianGupta
I think @Divy123 was already working on implementing this feature.
I would suggest closing this PR because it was not assigned to you.
Thanks.
cc: @jywarren

[Divy123]

@VibhorCodecianGupta I was working on this issue and following the discussion, you should have asked me if I was already working on it or not.
Since I am working on some other issues as well, it got a bit delayed. In #606 #488 also same thing happenned.
I request you to please close this PR so that a good workflow is maintained.

[vibhorgupta-gh]

@Divy123 Oh! That's totally my fault, I'm really sorry. Didn't mean to at all. I actually did not realise you had claimed this one, I had the wrong impression that you were working on module tests rather than code coverage 😅
I'll undo the code coverage stuff, and just leave the ui test part in. Apologies!
You can also take excerpts from my setup here and implement the same thing in your PR. It's all tested. Cheers.
cc: @jywarren

[vibhorgupta-gh]

This now addresses adding ui tests to travis. @jywarren
@Divy123 you can go ahead and implement codecov, apologies again!

[jywarren]

Very cool! Great work, @VibhorCodecianGupta !!!