2.1.1hotfix

Hotfix focused on stabilizing ingestion and cleaning up test changes.

What's Changed

• Non-image files in folder break ingestion by @naknomum in #68
• Image ingestion thread is dying in background by @naknomum in #73
• remove dummy ml option by @TanyaStere42 in #71
• Fix documentation links by @TanyaStere42 in #72
• fix error/death during gm.identify() on bad file by @naknomum in #74

Full Changelog: 2.1.1...2.1.1hotfix