Add role to ensure git is installed

Change-Id: I8dc4c4eaa593adb5a0f4bec6a2a5bea778a78bab

roles/tobiko-deploy/meta/main.yaml

@@ -2,3 +2,8 @@
 
 dependencies:
   - role: tobiko-common
+
+  - role: tobiko-ensure-git
+    when: >
+      (tobiko_git_repo is defined) or
+      (test_git_repo is defined)

roles/tobiko-ensure-git/tasks/main.yaml

@@ -0,0 +1,24 @@
+---
+
+- block:
+    - name: "get installed git version"  # noqa 303
+      shell: >
+        git --version
+      register: get_git_gersion
+
+  rescue:
+    - name: "install Git packages"
+      become: true
+      package:
+        name: git
+
+    - name: "get installed git version"  # noqa 303
+      shell: >
+        git --version
+      register: get_git_gersion
+
+
+- name: "show installed git version"
+  debug:
+    var: get_git_gersion.stdout
+    verbosity: 1