Fixing evaluation of response objects

In my modification earlier, I removed the is not None from the
conditionals. Unfortunately, a Response object from Requests will return
False if it is a 4xx error. Not cool!

Also, I split out the garbage into properties instead.

Change-Id: I74d122a57b2e60b591f894cb26a375b04f0b5939
Merge "Fixing evaluation of response objects"