Added sample method for exponential distribution
Added sample method for exponential distribution

smarden1/jstat,ggonzale/jstat,NorthDecoder/jstat,ggonzale/jstat,JeebsM/jstat,JeebsM/jstat,jstat/jstat,smarden1/jstat,akrawitz/jstat,jstat/jstat,NorthDecoder/jstat,cmpolis/jstat,jamescgibson/jstat,akrawitz/jstat