chore: Use ESLint comma-dangle with always-multiline

[ntwb]

Testing ESLint comma-dangle rule with always-multiline option

Ref #612

[ntwb]

This might be a little too ambitious...

I'll take a closer look at the ESLint comma-dangle options http://eslint.org/docs/rules/comma-dangle#options

[nylen]

This might be a little too ambitious...

How so? This is exactly what I'd like to see here, though it is already needing a rebase. Hopefully the changes were prepared using eslint --fix or some other quick and easy method.

[nylen]

Closing in favor of #741.