[wip] integrate automated face detection

[redshiftzero]

Status

in progress

Description of Changes

Fixes #6

Changes proposed in this pull request:

• using amazon rekognition to automatically detect faces and add them to the database (this blog post is what really sold me)
• to do: frontend - display autodetected faces on images displayed in the identification workflow

Notes for Deployment

• need to set up Redis on staging/prod servers

Tests and linting

• I have rebased my changes on current develop

• pytests pass in the development environment on my local machine

• flake8 checks pass

[redshiftzero]

This needs a rebase but still would be worthwhile. For any interested folks, the remaining pieces are still:

• Frontend development to expose the identified face on top of the image in the web UI
• Devops work to add redis to staging/prod