Move Wiki testing page to main docs?

[TomAugspurger]

Currently in contributing.rst we link to https://github.com/pandas-dev/pandas/wiki/Testing

Thoughts on having that as a separate page in the rst docs?

[jorisvandenbossche]

Yes, I think putting that in the developer section of the docs is a good idea (separate page, for now linked from the developer.rst page?)

[jreback]

yep

[jreback]

rather would maybe just expand some parts of: http://pandas-docs.github.io/pandas-docs-travis/contributing.html#test-driven-development-code-writing