Full Test Coverage for Box command [0.17.2]

[mikeschinkel]

We need to write tests for our own box command. This will actually be a significant undertaking because PHP has 11 subcommands many of which have their own subcommands and we have all the combinations of containers, which can lead to a large number of permutations.

Something for inspiration: https://phpunit.readthedocs.io/en/7.1/assertions.html