Move DD code into its own directory (#6)

reference/tests/util.py

@@ -0,0 +1,20 @@
+import ddtrace
+from contextlib import contextmanager
+
+
+def assert_dict_issuperset(a, b):
+    assert set(a.items()).issuperset(set(b.items())), \
+        '{a} is not a superset of {b}'.format(a=a, b=b)
+
+
+@contextmanager
+def override_global_tracer(tracer):
+    """Helper functions that overrides the global tracer available in the
+    `ddtrace` package. This is required because in some `httplib` tests we
+    can't get easily the PIN object attached to the `HTTPConnection` to
+    replace the used tracer with a dummy tracer.
+    """
+    original_tracer = ddtrace.tracer
+    ddtrace.tracer = tracer
+    yield
+    ddtrace.tracer = original_tracer