v1.1.0-beta.1: Fix tests

• Allow consumers to add their own checks (as an example - FT.com could add a specific check to test cache headers).
• Remove FT-specific "auth" option. In place, when programatically using you can add global headers. This means in n-heroku-tools we can specify

This is technically a breaking change, but since it's only n-heroku-tools that would break, i'll do a beta release and sync.

Also adds a networkRequests check - to check that requests have been made to URLs. Example - check that tracking works, or an ad request was made.