Correct validate parameter exception message
Added warnings to CORK EoS
Added warnings to CORK EoS
Changed validate param limits for cork_P
Added chemical potentials functions
Added chemical potential benchmark
added underscores to multiword functions
Changed validate param bounds to allow large minerals (like atg)
Removed print statements
fix tests
Merge PR #85 'Add chemical potentials'

Added chemical potential and fugacity functions and a minor bug fix for the
CORK, Modified Tait and SLB EoSs.