Looser tolerances in MatrixBuilder tests

Apparently the random numbers coming out of NumPy on MacOS/Anaconda are different from what Jim sees with Ubuntu's apt NumPy, and we need lower
tolerances to support both.
Looser default tolerances in shapelet comparison test utility functions

Apparently the random numbers coming out of NumPy on MacOS/Anaconda are different from what Jim sees with Ubuntu's apt NumPy, and we need lower
tolerances to support both.
Add absolute tolerances in shapelet comparison functions.
Merge branch 'u/jbosch/DM-1305'