lapack/testlapack: clean up and use isOrthogonal helper
Created by: vladimir-ch
Motivated by https://github.com/gonum/lapack/issues/234
At the moment I would not add a tolerance parameter to isOrthogonal
. 1e-13
is pretty tight and works for all current tests on my machine, so there is no real need for it. It can be added later if some finer control is necessary.
Please take a look.