Fix client regression from turbo mode refactor (#79)

* Fix client regression from turbo mode refactor

The turbo mode refactoring introduced a regression where the kubernetes
client can fail to find the kubeconfig. This happens because
get_api_client is called twice and the second time it is called without
the module being passed as an argument. Without this, the configuration
will use defaults. This will be a problem if the user has specified a
location for the kubeconfig that's different from default, for example.

* Add tests

molecule/default/tasks/full.yml

@@ -24,6 +24,38 @@
         that:
           - output is failed
 
+    - block:
+        - name: Copy default kubeconfig
+          copy:
+            remote_src: yes
+            src: ~/.kube/config
+            dest: ~/.kube/customconfig
+
+        - name: Delete default kubeconfig
+          file:
+            path: ~/.kube/config
+            state: absent
+
+        - name: Using custom config location should succeed
+          kubernetes.core.k8s:
+            name: testing
+            kind: Namespace
+            kubeconfig: ~/.kube/customconfig
+
+      always:
+        - name: Return kubeconfig
+          copy:
+            remote_src: yes
+            src: ~/.kube/customconfig
+            dest: ~/.kube/config
+          ignore_errors: yes
+
+        - name: Delete custom config
+          file:
+            path: ~/.kube/customconfig
+            state: absent
+          ignore_errors: yes
+
     - name: Ensure k8s_info works with empty resources
       k8s_info:
         kind: Deployment