eslint: tweak "comma-dangle" rule to accommodate curried functions

[davidchambers]

Reducing diff noise is one of the goals of this project. Trailing commas play a significant role. For example:

 const tokens = [
   'foo',
   'bar',
   'baz',
+  'quux',
 ];

In the Sanctuary world we only ever define curried functions. Functions are almost always applied to exactly one argument. Trailing commas are unhelpful in this context. For example:

return foo (
  bar (baz)
      (quux),
);

Unless foo is a “foreign” function it will never be applied to more than one argument; the trailing comma does not provide a potential benefit to future diffs.

This pull request tweaks the comma-dangle rule to prohibit rather than require a trailing comma after a function argument not immediately followed by a ).

[Avaq]

Looks good to me. We did the same.

[Avaq]

You don't want to add line breaks?

[Avaq]

Ah, for easier sorting?

[davidchambers]

I was following the existing formatting. This looks fine to me too:

Suggested change

	"comma-dangle": ["error", {"arrays": "always-multiline", "objects": "always-multiline", "imports": "always-multiline", "exports": "always-multiline", "functions": "never"}],
	"comma-dangle": [
	"error",
	{
	"arrays": "always-multiline",
	"objects": "always-multiline",
	"imports": "always-multiline",
	"exports": "always-multiline",
	"functions": "never"
	}
	],

I would like to remain consistent, though. :)

[Avaq]

I'd vote for no line breaks over adding line breaks to every rule, if those were the only choices. I don't mind either way though, which is why I already approved the PR.