Add gemma-wrapper...* guix.scm: New package propagated-input.
* README.md: Mention that you require "guix-bioinformatics" package, because
of the addition of "gemma-wrapper".
Add procedure for uploading gzipped file...* gn3/file_utils.py (extract_uploaded_file): New procedure.
* tests/unit/test_file_utils.py: Test cases for ^^.
* tests/unit/upload-data.tar.gz: New test data.