Handle redirects from the server

[mike-engel]

Closes #134

When we got rid of request in #62, we accidentally removed the ability to follow redirects, since node's http.request method doesn't have the ability to follow redirects. This will re-call the handler function when a status code is one of the four redirect types using the Location header from the response headers.

This also makes a few updates to how tests run:

• Makes all of the request tests run serially. This fixes fragile issues with race-conditions since we're stubbing the global https node module
  • This makes the tests a little slower, but is much more resilient to changes
• Combines the app and track api request tests into a single file
• Updates the browserlists definitions (transitive dependency) to get rid of the annoying errors in the console