Add Ansible playbook for grind workers

contrib/ci-workers/grind.yml

@@ -0,0 +1,27 @@
+---
+# Configure a Buildbot worker
+- include: unix.yml
+
+- name: Install grind-specific worker dependencies
+  hosts: zcash-ci-worker-unix
+  become: true
+
+  vars_files:
+    - vars/default.yml
+
+  tasks:
+    - name: Get dependencies for distribution
+      include_vars: "{{ item }}"
+      with_first_found:
+        - files:
+            - "vars/{{ ansible_distribution }}-{{ ansible_distribution_version }}.yml"
+            - "vars/{{ ansible_distribution }}-{{ ansible_distribution_major_version | int }}.yml"
+            - "vars/{{ ansible_distribution }}.yml"
+            - "vars/{{ ansible_os_family }}.yml"
+          skip: true
+
+    - name: Install required packages
+      package:
+        name: "{{ item }}"
+        state: present
+      with_items: "{{ grind_deps }}"