Add /usr/local/sbin to PATH

Some homebrew formulae, (e.g. [RabbitMQ][1]) link binaries here.

[1]: https://github.com/Homebrew/homebrew/blob/master/Library/Formula/rabbitmq.rb
include, filter, user
Revert "include, filter, user"

This reverts commit 383612ac4cb05641fce1a9b1051afd238365f69e.
Spell check git commits
Use POSIX compliant test command in git hooks

Ubuntu systems will error out on `[[` in shell scripts with `#!/bin/sh`
as the shebang.
Revert adding /usr/local/bin to path in zshenv

* Adding /usr/local/bin to path in `~/.zshenv` causes it to be in my path twice one right after the other. /usr/local/bin is already added to the path in the correct order on OSX Yosemite by the /etc/paths file. 

* Remove /usr/local/bin from path export in zshenv
Fix typo in zshenv path