Adapted for running alignment stage in session
Added genes 12S and 28S
Minor edit
Overhaul of BLAST process

— was having single sequence return issue
— this was due to the aligning of two sequences are prevented from
aligning — low complexity sequences
— I changed the BLAST process so that multiple sequences are always
being aligned. In the first instance, the sequences in the alignment
are BLASTed against species sequences to find overlap. After 5
sequences have been added, each species sequence is BLASTed against the
alignment sequences.
— I updated downloader._filter and tests as a result
— I need to update the BLAST test for alignmentblast