Need for Speed: Jandig API & Admin

What's Changed

• Improve API speed by avoiding HEAD requests to calculate Object and Marker sizes by @pablodiegoss in #618
• Improve Object and Marker admin pages by @pablodiegoss in #619
• Update Artwork and Exhibit admin pages by @pablodiegoss in #620
• Create CI/CD with GitHub Actions by @pablodiegoss in #621
• Improve Jandig DB queries by @pablodiegoss in #622
• Create factories to generate local testing data by @pablodiegoss in #623
• Add tests and coverage to CI by @pablodiegoss in #624
• Enable search in exhibit api by @pablodiegoss in #625
• Add API for user logins with simple jwt by @pablodiegoss in #626

Full Changelog: v1.4.2...v1.5.0