Changed tab width to 2 spaces
More efficient MantelTest

rewrote to use numpy arrays and made the shuffle matrix (SM) algorithm
more efficient by only shuffling the upper triangle.
Only skip structure score if less than two unique words

instead we’ll rely on the normality test as part of the Mantel test to
remove weird structure scores.
Fixed wrong argument name
Added script to randomize chain assignment

Given a list of chain codes and a number of generations, the script
outputs a random order in which to assign participants to the chains,
ensuring that e.g. A3 comes after A2 comes after A1, etc…
Failsafe should also send trial number

…when sending up a ready signal. Also adds a note to say that the
failsafe has been called which is indicative of a potential problem.