message: Change grammar
diff: @@ -347,7 +347,7 @@ pub fn report_coverage(config: &Config, result: &TraceMap) -> Result<(), RunErro
  }
  _ => {
  return Err(RunError::OutFormat(
  - "Format currently unsupported".to_string(),
  + "Output format is currently not supported!".to_string(),
  ));
  }
  }
  