add tests to the package

[zakariaharti]

[blvdmitry]

So this will be the list of what needs to be done.

1. Add component tests
2. Add yarn script to run them
3. Run tests on commit or in CI (? Depends on time it takes to test component and CI options on github)

I'm closing the other issue also, since this one will cover both

[zakariaharti]

awesome ! I'll open a PR for adding tests