Release v0.4.0

• Fixes
  Upgraded to latest packages (thanks, @fjogeleit)
  Fix for undo/redo (thanks @pomelyu)
  Issue #9 fixed
  Issue #10 and #15 you can no longer give dataUrl as value only as background image and/or by adding the image as an object
• Breaking Changes
  data and dataType properties have been replaced with value and defaultValue to be able to use the component as controlled component
  node support of 6,7 and 8
• New Features
  Ability to add an image as object