[EC][82715692] unify interface to ops-routes

- Prior to this commit: build-info was a map, env was a delay, config
  was a function. Now they're expected to be 0-ary functions which
  return maps. Motivating factor is developer friendliness.
[EC][82715692] document interface change in README
Merge pull request #4 from primedia/fun-att

[EC][82715692] unify interface to ops-routes