[BUG]: Checkbox trait doesn't remove attribute when unchecked

When html attributes are true or false, the should either exist or not exist.

For example, required. This don't have a value in HTML5.

• Valid (not required):<input type="text">
• Valid (required): <input type="text" required>
• Invalid (not required):<input type="text" required="false">
• Invalid (required):<input type="text" required="true">

When the HTML grapes is then rendered outside Grapes and the input is checked if it's required, this fails as Chrome always returns true is the required attributes is set... regardless of the value.

I've been looking into this myself but not figure it out yet but it looks like Components needs a removeAttribute function to handle this.

Sorry, but in a rush, so I'll provide fiddle on Monday...