Bump queue-worker and NATS

NATS moved its primary library to: github.com/nats-io/stan.go

This commit synchronises the library in the gateway to match the
queue worker.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

gateway/vendor/github.com/nats-io/stan.go/pb/protocol.proto

@@ -0,0 +1,146 @@
+// Copyright 2016-2018 The NATS Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Uses https://github.com/gogo/protobuf
+// compiled via `protoc -I=. -I=$GOPATH/src  --gogofaster_out=. protocol.proto`
+
+syntax = "proto3";
+package pb;
+
+import "github.com/gogo/protobuf/gogoproto/gogo.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_getters_all) = false;
+
+// How messages are delivered to the STAN cluster
+message PubMsg {
+  string clientID = 1;  // ClientID
+  string guid     = 2;  // guid
+  string subject  = 3;  // subject
+  string reply    = 4;  // optional reply
+  bytes  data     = 5;  // payload
+  bytes  connID   = 6;  // Connection ID. For servers that know about this field, clientID can be omitted
+
+  bytes  sha256  = 10; // optional sha256 of data
+}
+
+// Used to ACK to publishers
+message PubAck {
+  string guid  = 1; // guid
+  string error = 2; // err string, empty/omitted if no error
+}
+
+// Msg struct. Sequence is assigned for global ordering by
+// the cluster after the publisher has been acknowledged.
+message MsgProto {
+  uint64 sequence        = 1;  // globally ordered sequence number for the subject's channel
+  string subject         = 2;  // subject
+  string reply           = 3;  // optional reply
+  bytes  data            = 4;  // payload
+  int64  timestamp       = 5;  // received timestamp
+  bool   redelivered     = 6;  // Flag specifying if the message is being redelivered
+  uint32 redeliveryCount = 7;  // Number of times the message has been redelivered (count currently not persisted)
+
+  uint32 CRC32           = 10; // optional IEEE CRC32
+}
+
+// Ack will deliver an ack for a delivered msg.
+message Ack {
+  string subject  = 1; // Subject
+  uint64 sequence = 2; // Sequence to acknowledge
+}
+
+// Connection Request
+message ConnectRequest {
+  string clientID       = 1;  // Client name/identifier.
+  string heartbeatInbox = 2;  // Inbox for server initiated heartbeats.
+  int32  protocol       = 3;  // Protocol the client is at.
+  bytes  connID         = 4;  // Connection ID, a way to uniquely identify a connection (no connection should ever have the same)
+  int32  pingInterval   = 5;  // Interval at which client wishes to send PINGs (expressed in seconds).
+  int32  pingMaxOut     = 6;  // Maximum number of PINGs without a response after which the connection can be considered lost.
+}
+
+// Response to a client connect
+message ConnectResponse {
+  string pubPrefix        = 1;   // Prefix to use when publishing to this STAN cluster
+  string subRequests      = 2;   // Subject to use for subscription requests
+  string unsubRequests    = 3;   // Subject to use for unsubscribe requests
+  string closeRequests    = 4;   // Subject for closing the stan connection
+  string error            = 5;   // err string, empty/omitted if no error
+  string subCloseRequests = 6;   // Subject to use for subscription close requests
+  string pingRequests     = 7;   // Subject to use for PING requests
+  int32  pingInterval     = 8;   // Interval at which client should send PINGs (expressed in seconds).
+  int32  pingMaxOut       = 9;   // Maximum number of PINGs without a response after which the connection can be considered lost
+  int32  protocol         = 10;  // Protocol version the server is at
+
+  string publicKey     = 100; // Possibly used to sign acks, etc.
+}
+
+// PING from client to server
+message Ping {
+  bytes connID    = 1;  // Connection ID
+}
+
+// PING response from the server
+message PingResponse {
+  string error    = 1;  // Error string, empty/omitted if no error
+}
+
+// Enum for start position type.
+enum StartPosition {
+    NewOnly        = 0;
+    LastReceived   = 1;
+    TimeDeltaStart = 2;
+    SequenceStart  = 3;
+    First          = 4;
+  }
+
+// Protocol for a client to subscribe
+message SubscriptionRequest {
+  string        clientID       = 1;  // ClientID
+  string        subject        = 2;  // Formal subject to subscribe to, e.g. foo.bar
+  string        qGroup         = 3;  // Optional queue group
+  string        inbox          = 4;  // Inbox subject to deliver messages on
+  int32         maxInFlight    = 5;  // Maximum inflight messages without an ack allowed
+  int32         ackWaitInSecs  = 6;  // Timeout for receiving an ack from the client
+  string        durableName    = 7;  // Optional durable name which survives client restarts
+  StartPosition startPosition  = 10; // Start position
+  uint64        startSequence  = 11; // Optional start sequence number
+  int64         startTimeDelta = 12; // Optional start time
+}
+
+// Response for SubscriptionRequest and UnsubscribeRequests
+message SubscriptionResponse {
+  string ackInbox = 2; // ackInbox for sending acks
+  string error    = 3; // err string, empty/omitted if no error
+}
+
+// Protocol for a clients to unsubscribe. Will return a SubscriptionResponse
+message UnsubscribeRequest {
+  string clientID    = 1; // ClientID
+  string subject     = 2; // subject for the subscription
+  string inbox       = 3; // Inbox subject to identify subscription
+  string durableName = 4; // Optional durable name which survives client restarts
+}
+
+// Protocol for a client to close a connection
+message CloseRequest {
+  string clientID = 1;  // Client name provided to Connect() requests
+}
+
+// Response for CloseRequest
+message CloseResponse {
+  string error = 1; // err string, empty/omitted if no error
+}