Make SpanProcessor.on_start accept parent Context (#1251)

* context from Tracer.start_span is passed through to the SpanProcessor
* fix linting issue in falcon test app when linting with eachdist script
* fix global error handler test as it read installed extensions
* reset global Configuration object state after tests were run

instrumentation/opentelemetry-instrumentation-falcon/tests/app.py

@@ -5,6 +5,7 @@ import falcon
 
 class HelloWorldResource:
     def _handle_request(self, _, resp):
+        # pylint: disable=no-member
         resp.status = falcon.HTTP_201
         resp.body = "Hello World"