Turned solver/liquid.pyx into a Liquid Phase Batch Reactor.
Turned solver/liquid.pyx into a Liquid Phase Batch Reactor.

There is no pressure, and you initialize it with species 
concentrations (IN SI UNITS!) not mole fractions.

It looks like the ODEs were already neglecting volume changes
due to stoichiometry, so we don't need to change that here. 

KEHANG/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,nyee/RMG-Py,enochd/RMG-Py,enochd/RMG-Py,pierrelb/RMG-Py,chatelak/RMG-Py,comocheng/RMG-Py,pierrelb/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,faribas/RMG-Py,nickvandewiele/RMG-Py,faribas/RMG-Py,comocheng/RMG-Py