rebase: vendor dependencies for Vault API

Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/google.golang.org/protobuf/proto/checkinit.go

@@ -0,0 +1,71 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package proto
+
+import (
+	"google.golang.org/protobuf/internal/errors"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/runtime/protoiface"
+)
+
+// CheckInitialized returns an error if any required fields in m are not set.
+func CheckInitialized(m Message) error {
+	// Treat a nil message interface as an "untyped" empty message,
+	// which we assume to have no required fields.
+	if m == nil {
+		return nil
+	}
+
+	return checkInitialized(m.ProtoReflect())
+}
+
+// CheckInitialized returns an error if any required fields in m are not set.
+func checkInitialized(m protoreflect.Message) error {
+	if methods := protoMethods(m); methods != nil && methods.CheckInitialized != nil {
+		_, err := methods.CheckInitialized(protoiface.CheckInitializedInput{
+			Message: m,
+		})
+		return err
+	}
+	return checkInitializedSlow(m)
+}
+
+func checkInitializedSlow(m protoreflect.Message) error {
+	md := m.Descriptor()
+	fds := md.Fields()
+	for i, nums := 0, md.RequiredNumbers(); i < nums.Len(); i++ {
+		fd := fds.ByNumber(nums.Get(i))
+		if !m.Has(fd) {
+			return errors.RequiredNotSet(string(fd.FullName()))
+		}
+	}
+	var err error
+	m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+		switch {
+		case fd.IsList():
+			if fd.Message() == nil {
+				return true
+			}
+			for i, list := 0, v.List(); i < list.Len() && err == nil; i++ {
+				err = checkInitialized(list.Get(i).Message())
+			}
+		case fd.IsMap():
+			if fd.MapValue().Message() == nil {
+				return true
+			}
+			v.Map().Range(func(key protoreflect.MapKey, v protoreflect.Value) bool {
+				err = checkInitialized(v.Message())
+				return err == nil
+			})
+		default:
+			if fd.Message() == nil {
+				return true
+			}
+			err = checkInitialized(v.Message())
+		}
+		return err == nil
+	})
+	return err
+}