Current APPLPy Bugs:

1. MGF(X) comes out as a piecewise function for gamma,
	may need to add assumptions
2. Cannot handle functions that include abs(*) (Sympy problem)
3. Credible Set seems to return incorrect upper values in 
	the Bayes module (*** this is not a problem in credible set,
	it's an issue with convergence conditions in the variate 
	generation algorithm)
4. Problem in Queue when the initial number of customers in the
	system is equal to the number of servers. Problems
	looks like it could be related to mpmath

