Add initial test-integration suites

Uses go-check in order to separate integration tests into suites, and
have Setup and TearDown operations (on Suites and Tests) ; and use
libcompose to start the external dependencies to test on (like consul,
marathon, etcd, some http images, etc..).

- Update Godeps to get dependencies needed for the use of libcompose
- Setup initial suites and go-check + libcompose mini-framework
- Add some hacks related to libcompose, will be fixed later (when fixed
  upstream)

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

integration/fixtures/invalid_configuration.toml

@@ -0,0 +1,3 @@
+{
+    "who": ["am", "I", "?", "JSON"]
+}