refactor: combine with Ubuntu Provisioning repo

Combine with this repository with https://github.com/opdavies/ubuntu-provisioning
so that everything can be managed in one place, and add a role for each
piece of software.

roles/zsh-antigen/tasks/main.yaml

@@ -0,0 +1,5 @@
+---
+- name: Download
+  get_url:
+    dest: ~/.antigen.zsh
+    url: https://raw.githubusercontent.com/zsh-users/antigen/master/bin/antigen.zsh