Allow overriding responsiveOptions with update

[mestaritonttu]

There is an issue in react-chartist for this, offering some workarounds: fraserxu/react-chartist#38

Any other workarounds we can use before this is (hopefully) implemented?

Edit: I tried hacking it in chartist.js like this, but it is not working:

function update(data, options, responsiveOptions, override) {

...

if(responsiveOptions) {
  this.responsiveOptions = Chartist.extend({}, override ? this.responsiveOptions : this.responsiveOptions, responsiveOptions);
}