[VOL-1866] Changed module dependency to v12.0.0 of k8s client-go and v1.15.4 of k8s api/apimachinery in sync with other voltha components

Had to use pseudo-version corresponding to v12.0.0 of k8s client-go
because golang proxy is no longer serving the modules not complying
to Semantic Import Versioning rules including client-go v12.0.0.
Refer to https://github.com/kubernetes/client-go/issues/631 and
https://github.com/golang/go/issues/33558

Change-Id: I2e558bab7f0702f230761319eb5392a7d0532ea3
diff --git a/vendor/k8s.io/api/events/v1beta1/doc.go b/vendor/k8s.io/api/events/v1beta1/doc.go
index bd269c6..9bec7b3 100644
--- a/vendor/k8s.io/api/events/v1beta1/doc.go
+++ b/vendor/k8s.io/api/events/v1beta1/doc.go
@@ -15,6 +15,7 @@
 */
 
 // +k8s:deepcopy-gen=package
+// +k8s:protobuf-gen=package
 // +k8s:openapi-gen=true
 
 // +groupName=events.k8s.io
diff --git a/vendor/k8s.io/api/events/v1beta1/generated.proto b/vendor/k8s.io/api/events/v1beta1/generated.proto
index b3e565e..04eacbb 100644
--- a/vendor/k8s.io/api/events/v1beta1/generated.proto
+++ b/vendor/k8s.io/api/events/v1beta1/generated.proto
@@ -116,6 +116,7 @@
   optional k8s.io.apimachinery.pkg.apis.meta.v1.MicroTime lastObservedTime = 2;
 
   // Information whether this series is ongoing or finished.
+  // Deprecated. Planned removal for 1.18
   optional string state = 3;
 }
 
diff --git a/vendor/k8s.io/api/events/v1beta1/types.go b/vendor/k8s.io/api/events/v1beta1/types.go
index dc48ddb..eef4564 100644
--- a/vendor/k8s.io/api/events/v1beta1/types.go
+++ b/vendor/k8s.io/api/events/v1beta1/types.go
@@ -96,6 +96,7 @@
 	// Time when last Event from the series was seen before last heartbeat.
 	LastObservedTime metav1.MicroTime `json:"lastObservedTime" protobuf:"bytes,2,opt,name=lastObservedTime"`
 	// Information whether this series is ongoing or finished.
+	// Deprecated. Planned removal for 1.18
 	State EventSeriesState `json:"state" protobuf:"bytes,3,opt,name=state"`
 }
 
diff --git a/vendor/k8s.io/api/events/v1beta1/types_swagger_doc_generated.go b/vendor/k8s.io/api/events/v1beta1/types_swagger_doc_generated.go
index a15672c..bbc91ed 100644
--- a/vendor/k8s.io/api/events/v1beta1/types_swagger_doc_generated.go
+++ b/vendor/k8s.io/api/events/v1beta1/types_swagger_doc_generated.go
@@ -63,7 +63,7 @@
 	"":                 "EventSeries contain information on series of events, i.e. thing that was/is happening continuously for some time.",
 	"count":            "Number of occurrences in this series up to the last heartbeat time",
 	"lastObservedTime": "Time when last Event from the series was seen before last heartbeat.",
-	"state":            "Information whether this series is ongoing or finished.",
+	"state":            "Information whether this series is ongoing or finished. Deprecated. Planned removal for 1.18",
 }
 
 func (EventSeries) SwaggerDoc() map[string]string {
diff --git a/vendor/k8s.io/api/events/v1beta1/zz_generated.deepcopy.go b/vendor/k8s.io/api/events/v1beta1/zz_generated.deepcopy.go
index e52e142..779ebaf 100644
--- a/vendor/k8s.io/api/events/v1beta1/zz_generated.deepcopy.go
+++ b/vendor/k8s.io/api/events/v1beta1/zz_generated.deepcopy.go
@@ -70,7 +70,7 @@
 func (in *EventList) DeepCopyInto(out *EventList) {
 	*out = *in
 	out.TypeMeta = in.TypeMeta
-	out.ListMeta = in.ListMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
 	if in.Items != nil {
 		in, out := &in.Items, &out.Items
 		*out = make([]Event, len(*in))