Update mocha
Use newer system for programatic runner
Remove mocha-as-promised

It's magic was being broken by the promies-aplus-tests in such a way
that it looked like all the resolver tests were passing, when in fact 3
of them should have failed.
Revert "depend on nathan7/next-tick for now"

This reverts commit 845154ad01ca941554f9442c40f2c72256f28fd9.
timoxley/next-tick#5 got merged so there's no need to depend on the
fork.