Add authentication for remote

Tests/AppTests/AppTests.swift

@@ -12,7 +12,7 @@ final class AppTests: XCTestCase {
 
     func testEncodingContent() {
         let input = Message.Content(time: 1234567890, id: 23456789)
-        let data = input.bytes
+        let data = Array(input.encoded)
         let output = Message.Content(decodeFrom: data)
         XCTAssertEqual(input, output)
         let data2 = [42, 42] + data