ScaleTestMatzen: Add more tests

Elwig/Helpers/Weighing/SystecScale.cs

@@ -44,6 +44,8 @@ namespace Elwig.Helpers.Weighing {
             } else {
                 throw new ArgumentException("Unsupported scheme");
             }
+            Stream.WriteTimeout = 250;
+            Stream.ReadTimeout = 11000;
 
             if (empty != null) {
                 var parts = empty.Split(':');
@@ -105,7 +107,7 @@ namespace Elwig.Helpers.Weighing {
                 line = await reader.ReadLineAsync();
                 if (LogPath != null) await File.AppendAllTextAsync(LogPath, $"{line}\r\n");
             }
-            if (line == null || line.Length < 4 || !line.StartsWith("<") || !line.EndsWith(">")) {
+            if (line == null || line.Length < 4 || !line.StartsWith('<') || !line.EndsWith('>')) {
                 throw new IOException("Invalid response from scale");
             }