Add new test for tensor rotation.
Add new test for tensor rotation.

Generate 1000 random rotations and check the
quick 6x6 rotation gives the same result as
the direct 3x3x3x3 rotation with 8 nested
loops.

alanfbaird/MSAT,jwookey/MSAT,alanfbaird/MSAT,jwookey/MSAT,pusher96/MSAT,jwookey/MSAT,alanfbaird/MSAT,pusher96/MSAT,pusher96/MSAT