Abeeway Tracker firmware upgrade tool

# Requirements

```
sudo apt install -y python3-serial python3-xmodem
```

# Usage
- Switch the tracker to bootloader first
- Check for device port with **dmesg**
- Execute, e.g:

```
python3 xmodem-send.py -p /dev/ttyACM0 -f AssetTracker2_MIC4_2_release-v2.6-0.bin
```