Test Updated cost function to account for increased pyruvate residuals (affects fitting with input models)

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Implement updated cost function that accounts for increased expected pyruvate residuals (affects fitting with input models, but would not affect inputless model)

Found in Supplemental info of https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3762840/
Found through https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4833181/