General testing suggestions

After each major change it is good to manually check "extreme" cases like the shortest and the longest protein.

Following query yields the shortest proteins:

db.session.query(Protein.refseq, Protein.sequence).order_by(func.length(Protein.sequence)).limit(10).all()

NM_001190706
NM_001190706
NM_001190487
NM_001190452
NM_021104

And this one gives the longest:

db.session.query(Protein.refseq).order_by(-func.length(Protein.sequence)).limit(10).all()

NM_001267550
NM_001256850
NM_133378
NM_133437
NM_133432