BackgroundColor issue on melodic from source

[tomlogan501]

Hi

This error occurs to me when i try the plugin, I also add to change some import to QtWidgets from QtGui.

Traceback (most recent call last):
  File "/home/tsimon/media/Documents/rqt_ws/src/rqt_launchtree/src/rqt_launchtree/launchtree_widget.py", line 178, in _update_launch_view
    self._filter_launch_view()
  File "/home/tsimon/media/Documents/rqt_ws/src/rqt_launchtree/src/rqt_launchtree/launchtree_widget.py", line 336, in _filter_launch_view
    filter_launch_entry(self.launch_view.topLevelItem(idx))
  File "/home/tsimon/media/Documents/rqt_ws/src/rqt_launchtree/src/rqt_launchtree/launchtree_widget.py", line 325, in filter_launch_entry
    entry.setBackgroundColor(0, self._highlight_color if highlight else self._neutral_color)
AttributeError: 'LaunchtreeEntryItem' object has no attribute 'setBackgroundColor'

Did I need to change my version of python or add modules ?