fix typo in 'npm owner rm' test
sudo won't make a bad git-remotes dir (fixes #6548)

I would love to test this, but without something like a portable
fakeroot (or maybe some sort of complicated mocking of chownr), it's
more or less impossible to test.
owners handles scoped packages (closes #6542)
update changelog for npm@2.1.9
2.1.9
doc: add link to CoC