Fix Mocha require cycle

[acostalima]

When requiring Mocha from the test app, the following warning message is being displayed:

Require cycles are allowed, but can result in uninitialized values. Consider refactoring to remove the need for a cycle.

The message is being filtered out for the time being as a workaround. Although the runner appears to be working as expected, we must find a way to resolve this. Note that we can't use require('mocha'), otherwise Metro picks up the implementation for Node.