`onChange` triggers

[martin056]

• Calling clear() doesn't trigger onChange
• Calling undo() triggers onChange several (equal to the remaining lines) times

If the above points are not intentional, I can make a PR and fix them :)

[ziaongit]

I did it like bellow for clear.

 const handleOnchange = () => {
  // This will work for clear
  };
<CanvasDraw
 onChange={handleOnchange}
>

[embiem]

Should be the same issue as described in #93, so I'll close this and track the issue in 93.