Miscellaneous changes to make the script more robust and more flexible

v0.9

Add Python cache files to .gitignore and remove tracked __pycache__

v0.8

Minor fixes to keep up with nixplay website changes

v0.7

DO NOT USE 0.6 release
This has a bug fix to sample_config.json

Incremental release

Several fixes and improvements

Initial release

Initial release v0.5

Current features:

• Scan for image files recursively under a given directory
• Exclude files that are larger than a certain size
• Pick, at random, a specified number of image files from the above two criteria
• Upload the resulting images to a specified playlist on https://app.nixplay.com (after first clearing the playlist)