Zbarcam

- Add Python3.6 support, refs 5
- Fully migrated Android from PIL to Pillow, refs 13
- Handle Android runtime permissions, refs 30
- Fixe codes not detected on Android, refs 32
- Migrate from zbarlight to pyzbar, refs 32
- Migrate to Python3.6 and opencv 4, refs 33

- Fix zbarlight dependency in setup.py, refs 28
- Migrate to zbarlight 2.1, refs 18

- Provide Makefile, refs 15
- Setup continuous integration testing, refs 6, 14
- Speedup OpenCV compilation time, refs 16
- Migrated to zbarlight, refs 5, 13
- Introduced UI tests, refs 4
- Using non-root Docker container, refs 27
- Run UI tests from Travis, refs 26

- Full screen camera
- Kvlang refactoring
- File tree refactoring

- Integrated to kivy-garden

- Add camera start/stop