Returns {:ok, response} if an :ok is passed as a first parameter, or {:error, exception} if :error is passed.

# test/support/git_mock_http_client.ex
defmodule MyApp.GitMockHttpClient do
  import Mockingbird.Client

  def call(:get, "https://api.github.com/users/amencarini") do
    respond :ok, 200, """
    {
      "login": "amencarini",
      "id":1100003
    }
    """
  end
end