Initial k8s support in libplayground (#216)

* Initial k8s support in libplayground

* Make tasks never give up + custom event for k8s cluster status

k8s/factory_mock.go

@@ -0,0 +1,21 @@
+package k8s
+
+import (
+	"github.com/play-with-docker/play-with-docker/pwd/types"
+	"github.com/stretchr/testify/mock"
+	"k8s.io/client-go/kubernetes"
+)
+
+type FactoryMock struct {
+	mock.Mock
+}
+
+func (m *FactoryMock) GetKubeletForInstance(i *types.Instance) (*kubeletClient, error) {
+	args := m.Called(i)
+	return args.Get(0).(*kubeletClient), args.Error(1)
+}
+
+func (m *FactoryMock) GetForInstance(instance *types.Instance) (*kubernetes.Clientset, error) {
+	args := m.Called(instance)
+	return args.Get(0).(*kubernetes.Clientset), args.Error(1)
+}