termcolor: tweak reset escape

Write `Ansi::reset()` using `\x1b[0m` instead of `\x1b[m`.

This works around an AppVeyor bug: https://github.com/appveyor/ci/issues/1824

termcolor/src/lib.rs

@@ -973,7 +973,7 @@ impl<W: io::Write> WriteColor for Ansi<W> {
     }
 
     fn reset(&mut self) -> io::Result<()> {
-        self.write_str("\x1B[m")
+        self.write_str("\x1B[0m")
     }
 }