1.2.0

Added

• Ability to wait for everything to be sent to display with the TM1637_wait()
  function.
• Ability to get current display brightness with the TM1637_get_brightness()
  function.
• Refresh the state machine clock with TM1637_refresh_frequency().

Changed

• TM1637_display_word() can now also display a colon.
• The state machine (that sends data to TM1637) clockspeed is now adjusted
  for different system clocks.

Fixed

• Changelog dates now has correct year.