Fixes#196
This marks the test case as flaky, making it run at most 3 times. It is
enough for one of this runs to pass to consider this test case passed
and ran no more. If 3 consecutive runs of this test case fail, the test
case will be considered failed. It has been reported that running this
test case again makes it pass, usually. This approach is preferred over
marking it as xfail(strict=False) because most of the times the test
ends up passing after another run, so that in most of the cases we
can still benefit from running this test case (since if it is actually
failing because of a bug it will be reported as such after failing 3
times, making the team aware of an actual issue happening here).
* 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
