Everything now works pretty much like before, so we're not yet feeling a
lot of the benefit. Still to do:
- Remove all vestiges of Etcd config etc from the Fixtures struct
- Remove duplicated config
- Make Fixtures and APIServer constructors take 0 params
This is motivated by #162, but also involves changing the
NewFixtures(...) constructor which is the entry point to the whole
framework. We're removing the amount of config
you need to make it work, in line with #163.