Fix/met formulas

[wtscott31]

Main improvements in this PR:

This updates the list of metabolites that previously had no formulas. ardicdavis and I found formulas for some metabolites and furthermore added metabolite ids, and sources.

I hereby confirm that I have:

• [x] Tested my code with all requirements for running the model
• [x] Selected devel as a target branch (top left drop-down menu)
• [x] If needed, asked first in the Gitter chat room about this PR

Note: replace [ ] with [X] to check the box. PLEASE DELETE THIS LINE

[BenjaSanchez]

@wtscott31 Thanks for the interest in contributing to the yeast-GEM repo. However, we need to close this PR, as the branch in your fork was created from master and not from devel, so it would introduce undesired extra commits. Please remake your branch making sure to use as base devel.

Also, on next PR also make sure to change the model as well, running the function you created (this will be reflected in the model files, e.g. .xml, .txt and/or .yml).

Looking forward to your new PR!