upgrade mocha

[rianfowler]

Description

• mocha shows up as the first critical security warning in npm audit report
• upgrading mocha to the version recommended by npm
• fixed a couple of minor breaking configuration changes

Testing done

Screenshots

Acceptance criteria

• [ ]

Definition of done

• Events are logged appropriately
• Documentation has been updated, if applicable
• A link has been provided to the originating GitHub issue (or connected to it via ZenHub)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs

[rianfowler]

relying on the existing unit tests / CI to validate this change

[rianfowler]

compilers is no longer a valid option. also the order matters- our mocha-setup uses import and requires babel to run before it.

[rianfowler]

I'll probalby use yarn audit moving forward- the output was confusing to me so I thought it was different from npm audit so i generated a package-lock.json with npm i --package-lock-only and ran npm audit and got the same thing.

Problem was our audit report is so long because we have a ton of security violations and i just couldn't see the top of it. Had to bump up the buffer size limit on my terminal to see the top of the audit report

[rianfowler]

I don't see anything that will impact us in the major releases notes (nor any awesome new features we can use):

https://github.com/mochajs/mocha/releases/tag/v4.0.0
https://github.com/mochajs/mocha/releases/tag/v5.0.0
https://github.com/mochajs/mocha/releases/tag/v6.0.0

maybe we can use this to improve our error reporting: mochajs/mocha#3125