Format symbols

[BrandonE]

Purpose (TL;DR) - mandatory

Properly format JavaScript symbols. Related to sinon#1974.

How to verify - mandatory

1. Check out this branch
2. npm install
3. npm test. This PR adds a symbolic key to one of the objects in a unit test and verifies that it is rendered properly.

Checklist for author

• npm run lint passes
• References to standard library functions are cached.

[coveralls]

Pull Request Test Coverage Report for Build 103

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 9 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.5%) to 82.464%

---

Files with Coverage Reduction	New Missed Lines	%
formatio.js	9	82.46%

Totals
Change from base Build 100:	0.5%
Covered Lines:	94
Relevant Lines:	112

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💛 - Coveralls

[mantoni]

Thank you 👍

[mantoni]

Released in v.3.2.0.

[mroderick]

Very nice!

[bhousel]

Ahh it looks like this change is triggering failures on engines that don't support Object.getOwnPropertySymbols

I noticed this because our project uses PhantomJS for our tests, but IE11 support would also be an issue.
We can polyfill this as a workaround, but thought you'd want to know!
openstreetmap/iD#6001

[mantoni]

Thank you for letting us know @bhousel! We will run into the same issue with the Sinon test suite. I didn't think of IE 11 when reviewing. I'll prepare a patch.