v0.7.0

• [Breaking] Manage special characters by using Page Code tables (only PC437, PC865 and PC858 are currently implemented).
  The new method for Printer has a third parameter to specify the Page Code to use.
  Before:

  Printer::new(driver, Protocol::default())

  Now:

  Printer::new(driver, Protocol::default(), None)
  Printer::new(driver, Protocol::default(), Some(PageCode::PC858))

• Bump env_logger to 0.11.2
• Fix typo

See CHANGELOG.md for more details