update dev dependencies for supertest@1.1.0
update dev dependencies for supertest@1.1.0

SuperTest v1.1.0 upgraded most of its development dependencies; since we
monkey-patch SuperTest's test suite against SuperTest as Promised, we
also need to version-bump.

This means `npm test` won't succeed with this commit and old versions of
SuperTest; that's okay, since there's no easy way around that.

WhoopInc/supertest-as-promised,noppoMan/supertest-as-promised