Using Aspera for downloads (the previous release) did not work for all SRA accessions, as the FTP path indicated by the NCBI documentation is not always correct.
Instead, to get around the issue of writing large files to the root directory I am creating a cache folder within the `temp_folder` for each run, and symlinking `/root/public/ncbi/sra` to that folder.
This release has no changes in the outputs from the previous one -- it should just work on more SRA accessions.