add uri tests

[stavro]

After starting to add some tests, I realized that the current URI implementation is very broken. Some of these tests are still failing.

I strongly suggest deprecating the usage of keyword lists as arguments, and only use maps.

_Don't do this_:

  card = [
    card: [
      number: 424242424242,
      exp_year: 2014
    ]
  ]

_But, do this:_

  card = %{
    card: %{
      number: 424242424242,
      exp_year: 2014
    }
  }

Then you can delegate all of the query string formatting directly to Elixir's URI.encode_query implementation, which will handle it properly.

[coveralls]

Coverage increased (+5.07%) to 18.478% when pulling 5b979eb on stavro:master into 29c0076 on robconery:master.

[robconery]

Love it. I forked this from a dead repo and have been meaning to update the codebase - appreciate your help here :).

[stavro]

np!

If you want help trying to update some of this code and come up with a proper upgrade path let me know. I'm also on the elixir irc chatroom if you wanna talk about it.