Fixing bug for calculating flux when the reaction is given in a reaction
library

For bimolecular reactions coming from reaction libraries
RMG did not check the direction in which the reaction was given.
This led to incorrect flux being calculated.

In Reaction library B + C = A  k1
RMG finds reaction A = B + C
RMG old flux = k1 * [A]
Now it checks the direction and calculates the flux
RMG new flux = k1* Keq * [A]

We havent checked what happens in a pdep reaction!

It must also be noted that if in a reaction library
duplicates in different directions are given then this fix
will fail!!