staticGraphWithDragAndDrop, fix custom link props, bug fixing

Full Changelog

Fixed bugs:

• Drag&Drop does not work for leaf nodes after collapsing and "uncollapsing" #223
• [Sandbox] Fail to remove links / nodes in the live demo example #212
• Error clicking nodes composed of mdi-react icons #201

Closed issues:

• link.renderLabel is not true by default #210
• onDoubleClickNode #194

Merged pull requests:

• Fix uncollapsing nodes causes entire graph to be dragged #224 (danielcaldas)
• Fix/allow custom properties to pass on update for links #220 (danielcaldas)
• Feature/new config static graph with drag and drop #217 (danielcaldas)
• Fix/Fail to remove links / nodes in the live demo #216 (danielcaldas)
• Feature/allow pass function in link.label property #215 (danielcaldas)
• Run CI on node 10.14.0 (additionally) #214 (danielcaldas)
• Use setState to set highlightedLink #213 (danielcaldas)

Chore:

• Supporting spread operator for objects. Moving from Object.assign().
• Update cypress from v2.1.0 to v.3.4.1.
• Use UNSAFE_componentWillReceiveProps instead of componentWillReceiveProps TBD: migrate to static getDerivedStateFromProps(props, state)