v3.0.0

Added

• Added before and after signing events to hook onto
• Added testing framework (currently need full install and S3 buckets to run)
• Added url pre-signing and force file download tests
• Added support for AWS Signature Version 4 signing process

Changed

• Sets minimum version to Craft v3.1.5, same as craftcms/aws-s3 plugin
• Changed default signing process to use v4 instead of v2

Fixed

• Added support for downloads in folders (not just subfolders on the asset bucket) #3 #4