Update hamming.bats

[pedrobotolli]

A test was added to fail if the script accepts more than two arguments, because the exercise description specifies that exactly two arguments of equal length must be passed.

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[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!

[glennj]

Let's discuss potential changes to the track on the forum please, before you raise a PR.