This endpoint is meant to run on a server and receive callbacks from webpagetest.com.
It keeps a list of runs organized by domain, with some aditional metadata, such as browser name and version.

API:

/api/get/:domain
- returns a JSON array of objects representing test runs.
- the object have the following format: { id: "", connectivity: "", browser_name: "", browser_version: ""}

/api/all
- returns a JSON array containing all the test runs.

/api/domains
- returns an array containing all the domains for which we hold any results

/api/addDomain
- used as a callback for webpagetest.com
- has an id query parameter holding the test ID