Fixed parameter bug in DiscreteUniform
First draft of diagnostics
Implemented Geweke, Gelman-Rubin and Freeman-Tukey for PyMC 3
Fixed import in diagnostics
Added tests for Geweke and GElman-Rubin; moved examples into pymc folder
Merge branch 'diagnostics' of github.com:pymc-devs/pymc into diagnostics

Conflicts:
	pymc/diagnostics.py