KerucSettings object to be passed in as formal param

[ShadAhm]

Old:

<keruc-seatpicker
    data-data="seatsData"
    data-canvas-width="500"
    data-canvas-height="500"
    data-vacant-colour-bg="#76D75D"
    data-vacant-colour-fg="#C1F2B4"
    data-occupied-colour-bg="#F56979"
    data-occupied-colour-fg="#BB1F31"
    data-selected-colour-bg="#7854AF"
    data-selected-colour-fg="#472085"
></keruc-seatpicker>

Change instead to:

<keruc-seatpicker
    data-data="seatsData"
    data-settings="kerucSettings"
></keruc-seatpicker>

The keruc settings are to be defined in parent controller, like so:

scope.kerucSettings = {
    canvasWidth: 500,
    canvasHeight: 500,
    vacantColourBg: '#76D75D'
    // ... etc
};

Where a setting is not specified, the default values will be used.