Include references from PhosphoSite in the enzyme-substrate database #115
Description
We process PhosphoSite from two sources: the tabular and the BioPax. The former does not contain references, the latter we don't extract the PTMs from. We should use only the BioPax, for this we need to process also the PTMs from there together with references. See the dataio.get_phosphosite_new method (it's half ready).