Allow minimum spacing for colon_assignment_spacing

[ghost]

Aligning code can be very nice. So, it's a bummer that coffeelint doesn't allow to specify a minimum spacing (in contrast to exact specification) for the colon_assignment_spacing rule.

What do you think? How could this be implemented? What about something like this?:

    "colon_assignment_spacing ": {
        "name": "colon_assignment_spacing",
        "level": "ignore",
        "spacing": {
            "left": 0,
            "min_right": 1
        }
    },