Rule proposal: no-empty-line-separating-import

This is stylistic rule. I often see import statements separated one from another using arbitrary rules, e.g.

``` js
import yargs from 'yargs';
import getStdin from 'get-stdin';

import {
lintFiles,
lintText
} from './../../utilities';

import {
failHandler,
getTargetPaths,
outputReport
} from './../../utilities/bin';
```

This rule would enforce no spacing between import statements, i.e.

``` js
import yargs from 'yargs';
import getStdin from 'get-stdin';
import {
lintFiles,
lintText
} from './../../utilities';
import {
failHandler,
getTargetPaths,
outputReport
} from './../../utilities/bin';
```

The issue names no file or test path. Start by locating existing rule implementations and their tests in this JavaScript ESLint plugin; done means consecutive import statements no longer allow arbitrary blank-line separation, matching the compact example.

Written by the indexing model from the issue text.