Revert "Can't use mocha-as-promised syntax in beforeEach, unforunately"

This reverts commit f8fe776e47429fefb089a2fadd7f489720a2a242.
Revert "Change reference to require mocha"

This reverts commit 420e421e08af3be56930d34948c0cdd3229e7a78.
Revert "Got mocha-as-promised working (without mocha-hack), but tests are failing intermittently"

This reverts commit 6c8dedaf406eae53974cd12f833ad4dfe3203015.