New Time API and Updated Examples

This release adds Adafruit IO CircuitPython support for the new Adafruit IO Time API.

• Calling receive_time returns localized time to the CircuitPython RESTClient, based on the device's IP address, as a struct_time](https://circuitpython.readthedocs.io/en/3.x/shared-bindings/time/__init__.html#time.struct_time) #19

• Note: The previous /time endpoint returned a plaintext response, instead of json. This release removes plaintext-handling from the library.

• Updated all examples to match the Adafruit IO naming scheme in the PyPortal's secrets.py file.

To use in CircuitPython, simply install the Adafruit CircuitPython bundle.

Read the docs for info on how to use it.