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)


