Make git repos writable so that hard links work

When people try to zuul-cloner from not zuul user, it fails with making
hard links. We can prevent the hard linking - or we can just make them
writable.

Change-Id: If0601116c8f3b3db2a43d77f7c609ab7f2330e80

roles/fetch-zuul-cloner/tasks/main.yaml

@@ -15,3 +15,11 @@
     path: "{{ destination }}"
     mode: 0755
   become: yes
+
+- name: Make repositories writable so that people can hardlink
+  file:
+    path: "{{ ansible_user_dir }}/src"
+    state: directory
+    recurse: yes
+    mode: ugo+rw
+  become: yes