Files modified:
- submit_image
- submit_gallery
- _validate_gallery
- _upload_media
- _read_and_post_media

Added new import:
- from io import BytesIO

Previously, to submit an image to Reddit a filepath to an image stored on the local machine needed to be provided to PRAW to pass through to the Reddit API. This fork changes this behavior by implementing support for bytes objects through the io library. What this means in practical terms: in the original code, the filepath is referenced to retrieve the image file and convert it to bytes format anyway. Now the bytes of an image can be directly passed through while still retaining the original filepath functionality. This means an image retrieved from a server does not need to be downloaded before it can be uploaded: it's String implementation can be passed along to Reddit instead.