Add integ smoke tests to verify basic service calls

Verify we can make a successful servie call to each supported
service (except support).

The point of these tests to verify nothing's majorly broken.  This
will make a Describe/List call to a service and verify we get a
200 response back.

```
$ nosetests test_smoke.py
......................................
----------------------------------------------------------------------
Ran 38 tests in 16.924s

OK
```

cc @danielgtaylor