PCE: solve_PCEcoefs pt4.5, 'HermiteProbpoly', Issue #23 pt5
PCE: solve_PCEcoefs pt4.5, 'HermiteProbpoly', Issue #23 pt5

Remove 'HermiteProbpoly' testing scaffolding.

zat1gi/stochastic,zat1gi/stochastic,zat1gi/stochastic,zat1gi/stochastic