Add Bridge List Definition

broker/bridge-list.go

+package main
+
+import "sync"
+
+type bridgeListHolder struct {
+	bridgeInfo       map[[20]byte]BridgeInfo
+	accessBridgeInfo sync.RWMutex
+}
+
+type BridgeListHolder interface {
+	GetBridgeInfo(fingerprint [20]byte) (BridgeInfo, error)
+}
+
+type BridgeInfo struct {
+	DisplayName      string `json:"displayName"`
+	WebSocketAddress string `json:"webSocketAddress"`
+	Fingerprint      string `json:"fingerprint"`
+}