Two single-cell test cases have been added for reactingTwoPhaseEulerFoam
with an interface composition phase system. These are droplet
evaporation cases; one single- and one multi-component. The cases run
for every possible inert specie, and check that the results between the
runs are broadly similar.
The multi-component case shows some unphysical changes at the start due
to non-convergence of the pimple iteration during the initial transient.
This can be mitigated by reducing the time-step.
