v0.3.0

This release adds the following features:

• Add event summary string to event profile #259
• Implement thumbnail generation for video files #264
• Support for PostgreSQL databases #265, thanks @Rahel-A
• Support for storing media files on S3 object storage #266
• User database schema migration workflow #270
• List and upload missing media files #273

It also fixes the following issues:

• Correctly set birth and death ref indexes #252