message: db: rename PoolError::PostgresManagerCreationFailed
diff: @@ -20,7 +20,7 @@ impl Pool {
  config.database_url.as_str(),
  r2d2_postgres::TlsMode::None,
  )
  - .map_err(PoolError::PostgresManagerCreationFailed)?;
  + .map_err(PoolError::InvalidDatabaseUrl)?;
  let pool = r2d2::Pool::builder()
  .max_size(config.max_pool_size)
  @@ -97,8 +97,8 @@ impl<'a> std::ops::Deref for DerefConnection<'a> {
  #[derive(Debug, failure::Fail)]
  pub enum PoolError {
  - #[fail(display = "failed to create the PostgreSQL connection manager")]
  - PostgresManagerCreationFailed(#[fail(cause)] postgres::Error),
  + #[fail(display = "the provided database URL was not valid")]
  + InvalidDatabaseUrl(#[fail(cause)] postgres::Error),
  #[fail(display = "failed to create the connection pool")]
  PoolCreationFailed(#[fail(cause)] r2d2::Error),
  