Some people make a complicated Ansible role for this, but I'm only installing Homebrew once, so just run the install command from http://brew.sh/ in Terminal!
According to the Ansible installation docs, the preferred way to install for macOS is via pip, however I never got it to install with the recommended process and upgrade cleanly between versions. The Homebrew-installed ansible package works better for me.
brew install ansible
Yeah, just do that.
Ansible makes setup easy. This playbook is intended to run all its tasks as local actions, so an inventory file is not necessary.
ansible-galaxy install -r roles/requirements.yml
ansible-playbook --ask-become-pass dnorman-macbook.yml
Add default colors for iTerm: https://github.com/stephenway/monokai.terminal
Add default config and packages for Sublime (e.g.): https://packagecontrol.io/packages/Base16%20Color%20Schemes
Install safari-fido-u2f https://github.com/Safari-FIDO-U2F/Safari-FIDO-U2F