Country implements ordering

[TrilceAC]

Country implements a total ordering based on Country.code. This ordering is also comparable to any string. This solves #360

[kvesteri]

This needs at least couple of unit tests. Also why not use total_ordering decorator from functools module?

[TrilceAC]

I'll try to prepare some tests.

Regarding the use of tolta_ordering, if you want, I can use it. I did not just because of the note at total_ordering, and because it was easy to implemente the four methods

Note: While this decorator makes it easy to create well behaved totally ordered types, it does come at the cost of slower execution and more complex stack traces for the derived comparison methods. If performance benchmarking indicates this is a bottleneck for a given application, implementing all six rich comparison methods instead is likely to provide an easy speed boost.

Probably performance will never be an issue, but every little bit helps.

[kvesteri]

I'm all for code clarity and simplicity over micro-optimizations, hence please use total_ordering even if there is a small performance penalty (as there is with any decorators).

For tests you can just have single test method parametrized

@pytest.mark.parametrize(
   'assertion',
   [
       Country('FI') > Country('ES'),
       ...
   ]
)
def test_ordering(assertion):
    assert assertion

[TrilceAC]

I have implemented the changes that you propose. Please check.