message: Add a check for names starting with a digit
diff: @@ -135,6 +135,13 @@ fn check_name(name: &str) -> CargoResult<()> {
  name)
  }
  + if let Some(ref c) = name.chars().nth(0) {
  + if c.is_digit(10) {
  + bail!("Package names starting with a digit cannot be used as a crate name\n\
  + use --name to override crate name")
  + }
  + }
  +
  for c in name.chars() {
  if c.is_alphanumeric() { continue }
  if c == '_' || c == '-' { continue }
  