Update dependencies

Among others, this updates minio-go, so that the new "eu-west-3" zone
for AWS is supported.

vendor/google.golang.org/api/serviceuser/v1/serviceuser-gen.go

@@ -1817,17 +1817,6 @@ type HttpRule struct {
 	// Put: Used for updating a resource.
 	Put string `json:"put,omitempty"`
 
-	// ResponseBody: The name of the response field whose value is mapped to
-	// the HTTP body of
-	// response. Other response fields are ignored. This field is optional.
-	// When
-	// not set, the response message will be used as HTTP body of
-	// response.
-	// NOTE: the referred field must be not a repeated field and must be
-	// present
-	// at the top-level of response message type.
-	ResponseBody string `json:"responseBody,omitempty"`
-
 	// Selector: Selects methods to which this rule applies.
 	//
 	// Refer to selector for syntax details.
@@ -4106,8 +4095,9 @@ func (s *Usage) MarshalJSON() ([]byte, error) {
 // "google.example.library.v1.LibraryService.CreateBook"
 //         allow_unregistered_calls: true
 type UsageRule struct {
-	// AllowUnregisteredCalls: True, if the method allows unregistered
-	// calls; false otherwise.
+	// AllowUnregisteredCalls: If true, the selected method allows
+	// unregistered calls, e.g. calls
+	// that don't identify any user or application.
 	AllowUnregisteredCalls bool `json:"allowUnregisteredCalls,omitempty"`
 
 	// Selector: Selects the methods to which this rule applies. Use '*' to
@@ -4117,12 +4107,13 @@ type UsageRule struct {
 	// Refer to selector for syntax details.
 	Selector string `json:"selector,omitempty"`
 
-	// SkipServiceControl: True, if the method should skip service control.
-	// If so, no control plane
-	// feature (like quota and billing) will be enabled.
-	// This flag is used by ESP to allow some Endpoints customers to
-	// bypass
-	// Google internal checks.
+	// SkipServiceControl: If true, the selected method should skip service
+	// control and the control
+	// plane features, such as quota and billing, will not be
+	// available.
+	// This flag is used by Google Cloud Endpoints to bypass checks for
+	// internal
+	// methods, such as service health check methods.
 	SkipServiceControl bool `json:"skipServiceControl,omitempty"`
 
 	// ForceSendFields is a list of field names (e.g.