Move test_s3 into s3tests.functional, so it can be split to multiple files nicely.

s3tests/functional/utils.py

@@ -0,0 +1,14 @@
+def assert_raises(excClass, callableObj, *args, **kwargs):
+    """
+    Like unittest.TestCase.assertRaises, but returns the exception.
+    """
+    try:
+        callableObj(*args, **kwargs)
+    except excClass as e:
+        return e
+    else:
+        if hasattr(excClass, '__name__'):
+            excName = excClass.__name__
+        else:
+            excName = str(excClass)
+        raise AssertionError("%s not raised" % excName)