Update go dependencies

vendor/google.golang.org/grpc/internal/internal.go

@@ -20,17 +20,28 @@
 // symbols to avoid circular dependencies.
 package internal
 
-import "golang.org/x/net/context"
+import (
+	"context"
+	"time"
+)
 
 var (
-	// WithContextDialer is exported by clientconn.go
-	WithContextDialer interface{} // func(context.Context, string) (net.Conn, error) grpc.DialOption
-	// WithResolverBuilder is exported by clientconn.go
+	// WithResolverBuilder is exported by dialoptions.go
 	WithResolverBuilder interface{} // func (resolver.Builder) grpc.DialOption
+	// WithHealthCheckFunc is not exported by dialoptions.go
+	WithHealthCheckFunc interface{} // func (HealthChecker) DialOption
 	// HealthCheckFunc is used to provide client-side LB channel health checking
-	HealthCheckFunc func(ctx context.Context, newStream func() (interface{}, error), reportHealth func(bool), serviceName string) error
+	HealthCheckFunc HealthChecker
+	// BalancerUnregister is exported by package balancer to unregister a balancer.
+	BalancerUnregister func(name string)
+	// KeepaliveMinPingTime is the minimum ping interval.  This must be 10s by
+	// default, but tests may wish to set it lower for convenience.
+	KeepaliveMinPingTime = 10 * time.Second
 )
 
+// HealthChecker defines the signature of the client-side LB channel health checking function.
+type HealthChecker func(ctx context.Context, newStream func() (interface{}, error), reportHealth func(bool), serviceName string) error
+
 const (
 	// CredsBundleModeFallback switches GoogleDefaultCreds to fallback mode.
 	CredsBundleModeFallback = "fallback"