Fix For Handling of Header Types

What's Changed

• Correctly handle headers of different types by @justmobilize in #152

Full Changelog: 2.0.4...2.0.5

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

To use in CPython, pip3 install adafruit-circuitpython-requests.

Read the docs for info on how to use it.