Make sure we do not create DOM element when insertDefaultUI is false

[pronebird]

In our app we have voice only chat with custom UI.

Publisher configuration:

{
  insertDefaultUI: false, 
  videoSource: null
}

Current build breaks due to exception thrown by OpenTok JS library when DOM element is provided to OTPublisher when insertDefaultUI = false.

Fixes issue #3

[aiham]

Hi @pronebird, thanks for contributing!

Do you mind editing your PR to point to the dev branch instead? That's where I've been doing my development actually. If you'd like to have a go at it, could you add some unit tests to test/OTPublisher.spec.js, probably in the with session prop suite? Otherwise I'll add the tests myself.

I should be adding a CONTRIBUTING.md file explaining all this later today.

[pronebird]

@aiham I based my patch off dev branch and added test to make sure that container is not rendered when OTPublisher.properties is set to {insertDefaultUI: false}

[aiham]

@pronebird Thanks!