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/jwt/imports.go

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2018-2019 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.
+ */
+
+package jwt
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// Import describes a mapping from another account into this one
+type Import struct {
+	Name string `json:"name,omitempty"`
+	// Subject field in an import is always from the perspective of the
+	// initial publisher - in the case of a stream it is the account owning
+	// the stream (the exporter), and in the case of a service it is the
+	// account making the request (the importer).
+	Subject Subject `json:"subject,omitempty"`
+	Account string  `json:"account,omitempty"`
+	Token   string  `json:"token,omitempty"`
+	// To field in an import is always from the perspective of the subscriber
+	// in the case of a stream it is the client of the stream (the importer),
+	// from the perspective of a service, it is the subscription waiting for
+	// requests (the exporter). If the field is empty, it will default to the
+	// value in the Subject field.
+	To   Subject    `json:"to,omitempty"`
+	Type ExportType `json:"type,omitempty"`
+}
+
+// IsService returns true if the import is of type service
+func (i *Import) IsService() bool {
+	return i.Type == Service
+}
+
+// IsStream returns true if the import is of type stream
+func (i *Import) IsStream() bool {
+	return i.Type == Stream
+}
+
+// Validate checks if an import is valid for the wrapping account
+func (i *Import) Validate(actPubKey string, vr *ValidationResults) {
+	if !i.IsService() && !i.IsStream() {
+		vr.AddError("invalid import type: %q", i.Type)
+	}
+
+	if i.Account == "" {
+		vr.AddWarning("account to import from is not specified")
+	}
+
+	i.Subject.Validate(vr)
+
+	if i.IsService() && i.Subject.HasWildCards() {
+		vr.AddError("services cannot have wildcard subject: %q", i.Subject)
+	}
+	if i.IsStream() && i.To.HasWildCards() {
+		vr.AddError("streams cannot have wildcard to subject: %q", i.Subject)
+	}
+
+	var act *ActivationClaims
+
+	if i.Token != "" {
+		// Check to see if its an embedded JWT or a URL.
+		if url, err := url.Parse(i.Token); err == nil && url.Scheme != "" {
+			c := &http.Client{Timeout: 5 * time.Second}
+			resp, err := c.Get(url.String())
+			if err != nil {
+				vr.AddWarning("import %s contains an unreachable token URL %q", i.Subject, i.Token)
+			}
+
+			if resp != nil {
+				defer resp.Body.Close()
+				body, err := ioutil.ReadAll(resp.Body)
+				if err != nil {
+					vr.AddWarning("import %s contains an unreadable token URL %q", i.Subject, i.Token)
+				} else {
+					act, err = DecodeActivationClaims(string(body))
+					if err != nil {
+						vr.AddWarning("import %s contains a url %q with an invalid activation token", i.Subject, i.Token)
+					}
+				}
+			}
+		} else {
+			var err error
+			act, err = DecodeActivationClaims(i.Token)
+			if err != nil {
+				vr.AddWarning("import %q contains an invalid activation token", i.Subject)
+			}
+		}
+	}
+
+	if act != nil {
+		if act.Issuer != i.Account {
+			vr.AddWarning("activation token doesn't match account for import %q", i.Subject)
+		}
+
+		if act.ClaimsData.Subject != actPubKey {
+			vr.AddWarning("activation token doesn't match account it is being included in, %q", i.Subject)
+		}
+	} else {
+		vr.AddWarning("no activation provided for import %s", i.Subject)
+	}
+
+}
+
+// Imports is a list of import structs
+type Imports []*Import
+
+// Validate checks if an import is valid for the wrapping account
+func (i *Imports) Validate(acctPubKey string, vr *ValidationResults) {
+	toSet := make(map[Subject]bool, len(*i))
+	for _, v := range *i {
+		if v.Type == Service {
+			if _, ok := toSet[v.To]; ok {
+				vr.AddError("Duplicate To subjects for %q", v.To)
+			}
+			toSet[v.To] = true
+		}
+		v.Validate(acctPubKey, vr)
+	}
+}
+
+// Add is a simple way to add imports
+func (i *Imports) Add(a ...*Import) {
+	*i = append(*i, a...)
+}
+
+func (i Imports) Len() int {
+	return len(i)
+}
+
+func (i Imports) Swap(j, k int) {
+	i[j], i[k] = i[k], i[j]
+}
+
+func (i Imports) Less(j, k int) bool {
+	return i[j].Subject < i[k].Subject
+}