perform as many tests as possible with orthogonal polynomials

[nschloe]

It is well known that the map from the monomials integrals to integration formulas is ill-conditioned (see, e.g., Gautschi who pointed it out in great detail for Gaussian rules). Hence, sanity tests in quadpy can be improved by not checking against monomial integrals, but integrals of orthogonal polynomials.

• line segment
• triangle
• tetrahedron
• hexahedron
• quadrilateral
• pyramid
• wedge
• n-ball
• n-cube
• n-sphere
• sphere
• circle
• ball
• disk