`merge_geo.py` is undocumented and lacks a CLI

[dkoslicki]

Files are hard coded in it, no description of what it does, not CLI, etc.

[dkoslicki]

It might not even have the correct logic: it's discarding some column data (but leaving the column name), and on a re-run, it does not appear to populate the sample_id field.

It should be straightforward to just use the SRA_accession metadata directly from the SRA and join on the accession column as those are the same as the sample_id