Support Python 2.7
Python 2.7 support for this program requires only a few simple changes:
  - Add `from __future__ import print_function` for the print(..., end='') syntax
  - Change the format specifier from a regular string literal to a unicode string literal (`u'blah'`)
  - Use the unicode escape `\u00b0` for the degree symbol instead of writing the degree symbol directly in the source code.