Tests

[sbugosen]

To correct Implicit Gibbs Flowsheet v2

[Robbybp]

Just pushed the changes that I made during our debugging session today. I.e.:

• Remove .value in constraints
• Add bounds on "auxiliary input variables"

For me, this converges in 123 iterations (~20 s) to the solution that we discussed with pressure of 1e5 Pa and temperature of 354 K.