Add target gene name

[rvosa]

By doing a lookup on the accession numbers for the Erycina pusilla sequences, i.e. column 1 in genes.tsv, the target gene names (column 2) can be fetched and inserted in the tree visualizations.

[rvosa]

This issue relates to #3: if we are able to identify which tips are each others' orthologs and which are paralogs we would then be able to accurately place gene names on clades with reference to the name applied to the Erycina pusilla sequence.