CAT-601 Nickakhmetov/Update portal containers' python/anndata dependencies

[NickAkhmetov]

This PR

• updates containers to use miniconda3:4.12.0
• updates anndata from 0.7.1 to 0.8.0 to support upstream changes to azimuth pipeline
  • anndata files generated by anndata >= 0.8.0 can cause issues when read by anndata <0.8 due to on-disk file format revisions
• updates the test script to use the updated pip freeze command on all python containers and suppress docker logs in CI to avoid breaking travis limits
• updates test fixtures to reflect changes to anndata format/use categorical encoding 0.2.0
• updates version numbers to reflect bump in dependencies
• updates outdated CWL version references
• updates other dependencies as needed to get everything up to date

Changes to main.py to support dependency changes:

• ome-tiff-offsets - changed the import from skimage.external to importing from tifffile directly due to upstream changes https://github.com/hubmapconsortium/portal-containers/pull/122/files#diff-13ef1f2cefd78667be5c6db6154ca10fe605e725a9db9eed32187baca945dd33
• anndata-to-ui - wrapped the to_dense call in asarray to work around issue where zarr couldn't serialize a numpy matrix https://github.com/hubmapconsortium/portal-containers/pull/122/files#diff-35b306cef1aa0c2e0a593820c86438445b76a4bc115fd5402effb52b25a38a3a