util: asynchelper: aenter_stack bind lambdas

Signed-off-by: John Andersen <[email protected]>

Author: John Andersen

CHANGELOG.md

@@ -26,6 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - skel modules have `long_description_content_type` set to "text/markdown"
 - Base Orchestrator `__aenter__` and `__aexit__` methods were moved to the
   Memory Orchestrator because they are specific to that config.
+- Async helper `aenter_stack` uses `inspect.isfunction` so it will bind lambdas
 
 ## [0.2.0] - 2019-05-23
 ### Added

dffml/util/asynchelper.py

@@ -127,8 +127,7 @@ async def aenter_stack(
     if context_managers is not None:
         for key, ctxmanager in context_managers.items():
             if call:
-                # Bind if not bound
-                if hasattr(ctxmanager, "__self__"):
+                if inspect.isfunction(ctxmanager):
                     ctxmanager = ctxmanager.__get__(obj, obj.__class__)
                 setattr(
                     obj, key, await stack.enter_async_context(ctxmanager())