v.1.5.0

• Replaced temporary files with in-memory buffers which, at the expense of a bit higher RAM usage, prevents unnecessary I/O and may result in faster performance when working with slower disks.
• Added information about the running environment to the -v/--version CLI argument, so that you can check which python version is being used, as well as some information about required and optional third-party packages.
• Added a minimum space saving threshold (1% per file). Files are only replaced if the space saved is at least 1% of the original file size. Contributed by varnav@GitHub.
• Added a check for the presence of the required package Piexif.
• Added new methods intended to allow optimize-images to be imported and used as a package. The initial refactoring was kindly contributed by Tharindu N. (truethari@GitHub)
• Added custom exceptions to better support the public API.