Fix latest lints (#58)

Author: kevmoo

lib/cli_logging.dart

@@ -207,7 +207,7 @@ class AnsiProgress extends Progress {
   });
 
   AnsiProgress(this.ansi, String message) : super(message) {
-    io.stdout.write('${message}...  '.padRight(40));
+    io.stdout.write('$message...  '.padRight(40));
     _updateDisplay();
   }
 
@@ -236,7 +236,7 @@ class AnsiProgress extends Progress {
     if (isFinal || cancelled) {
       char = '';
     }
-    io.stdout.write('${ansi.backspace}${char}');
+    io.stdout.write('${ansi.backspace}$char');
     if (isFinal || cancelled) {
       if (message != null) {
         io.stdout.write(message.isEmpty ? ' ' : message);