ux-button custom type

[dspublic]

I'm submitting a feature request

• Library Version:
  0.14.1

• Current behavior:
  The typeChanged method of UXButton class doesn't allow a custom type value use.
  if (newValue == null || typeClasses.includes("ux-button--" + newValue) === false ) { newValue = 'raised'; }

• What is the expected behavior?
  I would like this;
  if (newValue == null ) { newValue = 'raised'; }

• What is the motivation / use case for changing the behavior?
  In this case, we can define a custom button style in css, and use it as type parameter:
  <ux-button type="custom-type"></ux-button>