test: Fix hanging tests
test: Fix hanging tests

Notes:

    > "Mocha will no longer force the process to exit once all tests
    > complete"
    >
    > - Mocha release v4

    We, therefore, have to supply `--exit` to force the process
    to exit.

References:

    * Mocha release v4: https://github.com/mochajs/mocha/releases/tag/v4.0.0

forfuturellc/mau