Merge pull request #3243 from jeff1evesque/feature-3242

#3242: Adjust 'README.md' regarding docker-compose

Merge pull request #3115 from jeff1evesque/bug-3099

#3099: Fix json dataset submission on web-interface

Merge pull request #3096 from jeff1evesque/feature-2869

#2869: Determine programmatic user login validation

Merge pull request #2876 from jeff1evesque/feature-2751

#2751: Ensure 'programmatic_interface' tests more specific

Merge pull request #2716 from jeff1evesque/feature-2712

#2712: Adjust 'README.md' to correspond to #5

Merge pull request #2448 from jeff1evesque/feature-2447

#2447: Reduce redundant fetch 'if (this.mounted)', add spinner

Merge pull request #2276 from jeff1evesque/bug-2274

#2274: cache_model.py, add 'else' case for no model found

Merge pull request #2082 from jeff1evesque/validate_mimetype

 #2081: Validate csv, json mimetypes