fix(DraggableCore): fix passing style

When using `React.cloneElement(this.props.children, props), we used to
override style by spreading it into another object. When that was removed,
we simply passed style on, unmodified. It appears some quirk of `cloneElement`
causes the render cycle to actually lose the value of `this.props.children.props.style`,
causing it to pass `undefined`.

This, of course, breaks just about everything.

Because this is affecting dependent packages I am pushing an update now then will
add a test to catch this.

Author: STRML

lib/DraggableCore.js

@@ -426,8 +426,6 @@ export default class DraggableCore extends React.Component<DraggableCoreProps, D
     // Reuse the child provided
     // This makes it flexible to use whatever element is wanted (div, ul, etc)
     return React.cloneElement(React.Children.only(this.props.children), {
-      style: this.props.children.props.style,
-
       // Note: mouseMove handler is attached to document so it will still function
       // when the user drags quickly and leaves the bounds of the element.
       onMouseDown: this.onMouseDown,