add listlabels method

Author: fanquake

Sources/CoreRPC/Labels.swift

@@ -0,0 +1,15 @@
+import Foundation
+import PromiseKit
+
+public extension CoreRPC {
+
+    enum LabelType: String, Codable {
+        case all = ""
+        case receive
+        case send
+    }
+
+    func listLabels(_ type: LabelType) -> Promise<[String]> {
+        return call(method: .listlabels, params: [type])
+    }
+}

Sources/CoreRPC/Methods.swift

@@ -41,6 +41,7 @@ public enum RPCMethod: String, Codable {
     case getzmqnotifications = "getzmqnotifications"
     case help = "help"
     case listbanned = "listbanned"
+    case listlabels = "listlabels"
     case listunspent = "listunspent"
     case listwalletdir = "listwalletdir"
     case listwallets = "listwallets"