style: normalize formatting

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---

Overview:

  - normalize function formatting:
      - function statement: `function f() {}`
      - function expression: `function() {}`

  - `disallowQuotedKeysInObjects: true` (e.g. `{foo: 42}` rather than `{'foo': 42}`)

  - `requireSpaceAfterLineComment: true` (e.g. `// comment` rather than `//comment`)

  - `validateIndentation: 4`

I prefer two spaces for indentation, and this style is currently used in some of the project's files, but __ramda.js__ itself uses four spaces so I went with that. If you'd like to switch to two spaces I'll update this pull request. :)

How is __ramda.api.js__ used?

I've added the following rules:

```javascript
disallowKeywordsOnNewLine: ['else', 'catch', 'finally'],
requireCurlyBraces: ['if', 'else', 'for', 'while', 'do', 'try', 'catch', 'finally'],
```

This means we will use this style everywhere:

```javascript
if (foo) {
    return bar;
} else {
    return baz;
}
```

Currently, we do this in a few places:

```javascript
if (foo) {
    return bar;
}
else {
    return baz;
}
```

And this in a few places:

```javascript
if (foo) return bar;
else return baz;
```

Speak up if you believe this is too restrictive.