alex-verve

There is at least one more race-condition in `PromisList` ``` File "/var/task/promise/promise.py", line 97, in try_catch return (handler(*args, **kwargs), None) , File "/var/task/graphql/execution/executor.py", line 260, in resolved , File "/var/task/graphql/execution/executor.py",...

Also getting these errors (14 times per 2.5 million requests) ``` File "/var/task/graphql/execution/executor.py", line 218, in complete_value_catching_error completed = complete_value(exe_context, return_type, field_asts, info, result) , File "/var/task/graphql/execution/executor.py", line 262, in...

I think I fixed the problem. Review is welcome https://github.com/syrusakbary/promise/pull/89