Auto merge of #2707 - sbeckeriv:banned-list-2699, r=alexcrichton

Ban keywords from crate names

Dearest Reviewer,

This pull request extends the banned list of project names to include
all of the current keywords for rust. I got the list of keywords from
https://doc.rust-lang.org/grammar.html#keywords . This
closes #2699 . The original ticket said warn but I figured how test is
handled is most likely how all banned names should be handled.

Oddly enough a few keywords have made their way to the crates.io. fn and
proc are both examples I found spot checking keywords. I do not there is
any action to take on those crates.

Thanks
Becker