add restic integration for doing pod volume backups/restores

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/util/test/mock_pod_command_executor.go

@@ -0,0 +1,17 @@
+package test
+
+import (
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/mock"
+
+	"github.com/heptio/ark/pkg/apis/ark/v1"
+)
+
+type MockPodCommandExecutor struct {
+	mock.Mock
+}
+
+func (e *MockPodCommandExecutor) ExecutePodCommand(log logrus.FieldLogger, item map[string]interface{}, namespace, name, hookName string, hook *v1.ExecHook) error {
+	args := e.Called(log, item, namespace, name, hookName, hook)
+	return args.Error(0)
+}