adding Paul Baker's sample utility module

[astrolamb]

Adding @paulthebaker 's utility module to add jump proposals and empiricial distributions easily!

[paulthebaker]

These functions should be added to existing modules rather than starting a new module. enterprise_extensions.sampler is probably the right place for most of it.

[AaronDJohnson]

There are some linting issues. You can run flake8 on the code to see where these are (or look at the logs).