reaction references

[mihai-sysbio]

Description of the issue:

Looking into the model in .mat and .yml files, neither seem to have references. Only 11 show up referring to "10.1093/femsyr/foy046".

Expected feature/value/output:

A structured "references" field as implemented in SysBioChalmers/Human-GEM#254

Current feature/value/output:

Pretty much no reaction references.

I hereby confirm that I have:

• Checked that a similar issue does not exist already