Add 'shouldFailWithMessage' test helper

🧐 Motivation Exactly as described in issue’s title 😃.

📝 Details First of all, thanks for prividing this awesome framework. It makes creating secure smart contracts actually possible!

I’ve been importing functions from openzeppelin-solidity/tests/helpers to use in my own tests for a couple of weeks. They work perfectly so there’s no need to craft my own. Helpers in shouldFail.js have been particularly useful.

Aside, from the canned shouldFail[reverting,throwing,outOfGas] helpers, I think the generic shouldFailWithMessage is flexible and can be used to check for different failure reasons. However, it is not exported by the module.

I suggest exporting it so it could be used externally when neither of reverting, throwing, outOfGas fill the bill.

I will follow up with a one liner PR to introduce that change.

Thanks!

[remon-nashid]

Working on exporting test helper + adding unit tests for the helper itself.

[nventuro]

This was added to https://github.com/OpenZeppelin/openzeppelin-test-helpers