Configure kubectl for checkers playbook

We made these changes to the deploy playbook, we need to mirror
them in the checkers playbook too.

Change-Id: Id713bd161c00f29049b6af786351a95f8dcb53c4

playbooks/checkers.yaml

diff --git a/playbooks/checkers.yaml b/playbooks/checkers.yaml
index 8f86c78..d3819dd 100644
--- a/playbooks/checkers.yaml
+++ b/playbooks/checkers.yaml
@@ -1,10 +1,13 @@
 - name: Update checkers
   gather_facts: false
   hosts: localhost
+  environment:
+    KUBECONFIG: "{{ ansible_user_dir }}/.kube/config"
   tasks:
     - name: Add scheduler to inventory
       add_host:
         name: 'zuul-scheduler-0'
+        ansible_kubectl_config: "{{ ansible_user_dir }}/.kube/config"
         ansible_kubectl_namespace: zuul
         ansible_connection: kubectl
     - name: Load checker data