Misc modifications for pytest comppatibility...
Misc modifications for pytest comppatibility
1) remove objects creations `ip = get_ipython()` which is anyway
injected in builtins.
2) use proper xunit test cases for capturing warnings.
3) Use proper assertWarns instead of assert print, as pytest captures
warnings.
4) fix recusrsion limit in pytest whcih need to be higher
5) properly capture context in yielded tests.
