message: use static variable for file names
diff: @@ -52,6 +52,8 @@ impl From<serde_yaml::Error> for Error {
  pub type Result<T> = result::Result<T, Error>;
  +static FILENAME : &'static str = "config.yml";
  +
  /// config of a given Wallet
  ///
  #[derive(Debug, Serialize, Deserialize)]
  @@ -102,12 +104,12 @@ impl Config {
  fs::DirBuilder::new().recursive(true).create(path.clone())?;
  let mut tmpfile = TmpFile::create(path.clone())?;
  serde_yaml::to_writer(&mut tmpfile, self)?;
  - tmpfile.render_permanent(&path.join("config.yml"))?;
  + tmpfile.render_permanent(&path.join(FILENAME))?;
  Ok(())
  }
  pub fn from_file<P: AsRef<Path>>(name: &P) -> Result<Self> {
  - let path = ariadne_path()?.join("wallets").join(name).join("config.yml");
  + let path = ariadne_path()?.join("wallets").join(name).join(FILENAME);
  let mut file = fs::File::open(path)?;
  serde_yaml::from_reader(&mut file).map_err(Error::YamlError)
  }
  @@ -154,7 +156,7 @@ impl Accounts {
  let mut tmpfile = TmpFile::create(dir.clone())?;
  serde_yaml::to_writer(&mut tmpfile, account_cfg)?;
  - tmpfile.render_permanent(&dir.join(format!("wallet-{}.yml", account)))?;
  + tmpfile.render_permanent(&dir.join(format!("{}{}.yml", account::PREFIX, account)))?;
  }
  Ok(())
  }
  @@ -171,8 +173,8 @@ impl Accounts {
  if entry.file_type()?.is_dir() { continue; }
  let name = entry.file_name();
  if let Some(name) = name.to_str() {
  - if name.starts_with("wallet-") && name.ends_with(".yml") {
  - let index = name.trim_left_matches("wallet-").trim_right_matches(".yml").parse::<u32>()?;
  + if name.starts_with(account::PREFIX) && name.ends_with(".yml") {
  + let index = name.trim_left_matches(account::PREFIX).trim_right_matches(".yml").parse::<u32>()?;
  to_read.insert(index, name.to_owned());
  indices += 1;
  }
  @@ -196,6 +198,8 @@ impl Accounts {
  pub mod account {
  use wallet_crypto::{bip44, coin::Coin, wallet::{Account}, hdwallet::{XPub}};
  + pub static PREFIX : &'static str = "account-";
  +
  #[derive(Debug, Serialize, Deserialize)]
  pub struct Config {
  pub alias: Option<String>,
  