probability

I found several useful applications of pseudo-random number sampling in the past. In particular:

• Inverse transform sampling
• Gibbs sampling

(This issue serves a reminder to add the respective methods. Pull requests always welcome.)

sbt experiment command in root should execute all experiments (c.f. flex.experiment package). However, for now, only one experiment is executed (with arg0). Therefore, the experiment command that does not have an argument must perform all the experiment codes. See Tasks.