Import gene sequences from fa.gz IGC file
Add script to allow loading of gene sequences from the .gz
file that we can find here :https://db.cngb.org/microbiome/genecatalog/genecatalog_human/
manage.py import_igc_sequences /path/to/file.fa.gz
Needs to have genes created first. This might change in the future to perform directly creation of gene with sequences
Closes #98