implement a .Fit for Pareto.  Doesn't do anything with weights.

(cherry picked from commit 8773c5df11c02e9ae3a529b4be27388a1e8bbd39)
Updating Box viewer classes to not hold by default.
Adding Beta distribution fitting.
Merge pull request #18 from aggieben/development

Implementing a .Fit for the Pareto distribution.
Adding fitting and sampling methods to the Pareto distribution.
Merge remote-tracking branch 'upstream/development' into development