remove unused import in test_yahoo
Merge pull request #3813 from gliptak/patch-2

remove unused import in test_yahoo
TST: Add building docs task to non-us build.
BLD: Add useful shortcuts to Makefile

BLD: Add doc task to Makefile
BLD: Make doc not silent

BLD: add tasks to .PHONY

BLD: Only remove *.pyc with make build
BLD: Add IPython to install.sh

BLD: Add IPython and sphinx to print_versions.py