Add tests

[padarom]

We should probably have some tests that auto-run before publishing to CocoaPods in case we break something either via a generate or API changes.

The following things could be under test:

• Compilability (tests will obviously fail before even running)
• Display consistency (e.g. via https://github.com/uber/ios-snapshot-test-case)

I don't think testing against our API is strictly necessary.

Also see https://guides.cocoapods.org/using/test-specs.html

[rafiki270]

@padarom There is a jenkins setup on ci.liveui.io, you only have to add a Jenkinsfile to get a CI working