Updated version of adafruit-circuitpython-ahtx0 library with bugfix

Newer AHT20s do not work, as they use a different calibration command as stated here : adafruit/Adafruit_CircuitPython_AHTx0#17 (comment)

To fix this problem the version should be bumped to the current one where they try the old and new calibration command. So far no other problems occured with this bugfix.

Author: d00mfish

mycodo/inputs/ahtx0_circuitpython.py

@@ -36,7 +36,7 @@
     'dependencies_module': [
         ('pip-pypi', 'usb.core', 'pyusb==1.1.1'),
         ('pip-pypi', 'adafruit_extended_bus', 'Adafruit-extended-bus==1.0.2'),
-        ('pip-pypi', 'adafruit_ahtx0', 'adafruit-circuitpython-ahtx0==1.0.5')
+        ('pip-pypi', 'adafruit_ahtx0', 'adafruit-circuitpython-ahtx0==1.0.21')
     ],
 
     'interfaces': ['I2C'],