Update requirements.txt with tested lib-version
Update requirements.txt with tested lib-version

Update requirements.txt with tested lib versions to prevent incompatibilities.
kiok46/kivy-designer,aron-bordin/kivy-designer,kivy/kivy-designer,aron-bordin/kivy-designer,kivy/kivy-designer,kivy/kivy-designer,kivy/kivy-designer,aron-bordin/kivy-designer