message: move the crc32 test in submodule for tests only
diff: @@ -60,8 +60,11 @@ pub fn crc32(input: &[u8]) -> u32 {
  })
  }
  +#[cfg(test)]
  +mod tests {
  #[test]
  -fn crc32_test() {
  + fn crc32() {
  let s = b"The quick brown fox jumps over the lazy dog";
  - assert_eq!(0x414fa339, crc32(s));
  + assert_eq!(0x414fa339, super::crc32(s));
  + }
  }
  