Merge pull request #5 from openwebwork/develop

Bring the develop branch up to date with the main repo
Merge pull request #8 from openwebwork/develop

Bring develop up to date.
Changed the routine that generates a Bernoulli random variable to return optional values for success vs failure.
Merge pull request #82 from KellyBlack/black_dev

Change the generation of a Bernoulli generated random variable to also include optional values to return.

I checked the old functionality and the new functionality.  Both seem to work.