Handle multiple parameters on a line when fixing arrow_alignment problems

Raised in #312, puppet-lint wouldn't handle multiline resources where multiple parameters were on the same line (it would align everything to the last parameter on the line). Now it properly moves the additional parameters onto their own lines before fixing the arrow alignment.

```puppet
user { 'test':
    a => 'foo', bb => 'bar',
    ccc => 'baz',
}
```

Before
```puppet
user { 'test':
    a              => 'foo', bb => 'bar',
    ccc            => 'baz',
}
```

After
```puppet
user { 'test':
    a   => 'foo',
    bb  => 'bar',
    ccc => 'baz',
}
```

Closes #312