Add tidy role for http://www.html-tidy.org/

roles/tidy/tasks/Darwin.yaml

@@ -0,0 +1,5 @@
+---
+- name: install homebrew package
+  homebrew:
+    name: tidy-html5
+    state: latest

roles/tidy/tasks/Debian.yaml

@@ -0,0 +1,5 @@
+---
+- name: install apt package
+  apt:
+    name: tidy
+    state: latest

roles/tidy/tasks/main.yaml

@@ -0,0 +1,2 @@
+---
+- include_tasks: '{{ansible_os_family}}.yaml'