message: Fix attrib encoding in libVCX for integers.
diff: @@ -6,7 +6,7 @@ use error::prelude::*;
  pub fn encode(s: &str ) -> VcxResult<String> {
  match s.parse::<u32>() {
  - Ok(_) => Ok(s.to_string()),
  + Ok(val) => Ok(val.to_string()),
  Err(_) => {
  let hash = sha256(s.as_bytes());
  let bignum = match BigNum::from_slice(&hash) {
  @@ -56,6 +56,10 @@ mod test{
  let number_as_string = "123";
  assert_eq!(number_as_string, encode(number_as_string).unwrap());
  +
  + let number_with_leading_zero_as_string = "0123";
  + let expected_encoded_number_with_leading_zero_as_string = number_as_string;
  + assert_eq!(expected_encoded_number_with_leading_zero_as_string, encode(number_with_leading_zero_as_string).unwrap());
  }
  