Pi Cam module V1.x support (confirmed not working with camera hardware V1.3 & python 3.7)

[JedrzejMajko]

If you like to widen support of this lib:
using your example with file location change only using Pi Cam V1.3 I get:

Traceback (most recent call last): File "camx.py", line 6, in <module> sensor_mode=0 File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/picamraw/main.py", line 26, in __init__ bayer_array, bayer_order = extract_raw_from_jpeg(filepath, camera_version, sensor_mode) File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/picamraw/main.py", line 93, in extract_raw_from_jpeg raw_bytes = _get_raw_bayer_bytes(jpeg_data_as_bytes, camera_version, sensor_mode) File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/picamraw/main.py", line 325, in _get_raw_bayer_bytes raise ValueError('Unable to locate Bayer data at end of buffer') ValueError: Unable to locate Bayer data at end of buffer

raw generated with command:
raspistill --raw -o raw.jpg

[jason-curtis]

The maintainers only have camera module V2 around to test with, but we would certainly consider a PR to extend support to V1.x modules.