Testing

[yoshuawuyts]

We should have a proper testing strategy. There's probably a few things we should do:

• test stores in Node
• test component lifecycles
• assert rendering works for views

Possibly bonus:

• test service workers with sw-test-env
• snapshot testing components

We might need to write some packages to wrap this up nicely.

[jbergstroem]

Getting users of create-choo-app into e2e'ing via puppeteer also seems like a Nice Practice since it so conveniently scales to CI.