Fix rename for MultiIndex columns DataFrame

[ogiaquino]

DataFrame rename doesn't rename a MultiIndex column and it flattens the columns. Closes #3165 which is a fix for index but not columns.

[jreback]

can u hook up to Travis?
instructions in contributing.md in main dir

also pls add a release notes mention

[ogiaquino]

Okay I think I've hooked it up to Travis. Do I have to run manual build?

[jreback]

push another commit or

git commit --amend -C HEAD (will reset the latest coit hash)

then

git push yourfork yourbranch -f

then Travis will build it

[ogiaquino]

Should I add the release note mention here? doc/source/v0.11.1.txt

[jreback]

release notes in doc/source/release.rst

[jreback]

ok...looks fine, except need to rebase, don't want to have those Merge branch in there....

git checkout yourbranch
git rebase -i

and remove the offending commit (just delete it) 05bd8618ab21701f7067969e84c9200c88ed4848

also prob want to s squash commits together

then

git push yourfork yourbranch -f

will rewrite this branch

[ogiaquino]

Sorry I'm still learning git, I hope I did your last instruction right, but I'm lost with deleting the commit Merge branch.
When I do git rebase -i the offending merge commit is not even there, I just proceeded with squashing, and after saving git log doesn't show the merge commit anymore.

[brandonkane]

Thanks for the fix, I ran into the same problem today and was about to start on a fix but you beat me to it. :)

I have tested your code and it works as expected for me, matching the functionality for indexes already put in by 3165.

Let me know if there is anything I can do to help.

[hayd]

@ogiaquino it looks like you rebased successfully, good work!