Biolink Api Versions Save

• merges PR #388: typo in 'category', should be 'categories'
• merges PR #392: adds taxon label ID to mapper endpoint
• merges PR #394: fixes typo in scigraph call (credit: @gaurav)
• various hotfixes related to python3.8 support, broken dependencies

• Fixes dockerfile

• Add MME endpoints, see https://github.com/biolink/biolink-api/pull/382

• Improvements to sim endpoints to prevent ddos queries, see: https://github.com/biolink/biolink-api/pull/381

Fixes to allow biolink to correctly construct self-URLs when being served from behind an SSL-terminating proxy, see https://github.com/biolink/biolink-api/pull/377

• Updated to ontobio 1.17.5
• Adds a Dockerfile
• Refactor sim endpoints to improve start up speed