Added banMember method

lib/Client/Client.js

@@ -304,6 +304,27 @@ var Client = (function (_EventEmitter) {
 		});
 	};
 
+	//def banMember
+
+	Client.prototype.banMember = function banMember(user, server) {
+		var length = arguments.length <= 2 || arguments[2] === undefined ? 1 : arguments[2];
+		var callback = arguments.length <= 3 || arguments[3] === undefined ? function (err) {} : arguments[3];
+
+		var self = this;
+		return new Promise(function (resolve, reject) {
+			if (typeof length === "function") {
+				// length is the callback
+				callback = length;
+			}
+			self.internal.banMember(user, server, length).then(function () {
+				callback();
+				resolve();
+			})["catch"](function (e) {
+				callback(e);reject(e);
+			});
+		});
+	};
+
 	return Client;
 })(EventEmitter);