Converting Signor pathways to GO-CAM

gocamgen and ontobio. Also, complex info lookup file ("SIGNOR_complexes.csv") is currently hard-coded in and should be downloaded from here before running. Will soon make this a changeable parameter.

Specify Signor pathway file (-f) as input and an outfile path with -o:

python3 pathway_importer.py -f "SIGNOR-G2-M_trans_02_03_18.tsv" -o "outfile.ttl"