Enhacement 9 ux for draggable panel

Au menu
- Handle responsive columns with using KeptColumns
- fix buggy drap 'n drop
- add a window config file for jest (not sure if jest config is also broke for mac / linux)

Hope it's KISS enought ;)
cf https://github.com/facebook/jest/issues/100 
so i'll try to fix it the cleaner I can by adding anoter config file, hoping the issue will be close soon.