* async inference support

* implemented concurrent decorator

* fixes for Python versions < 3.7

* async methods depend on python version

* revert changes in forward method

* async_test -> async_simple_test, debug logging is done via logger.debug

* add async test

* add asynctest to test requirements

* async tests are run in Python 3.7

* check CUDA, add docs

* fix device

* run test only if CUDA is available

* fix linting

* custom operators can run on nondefault stream

* set current stream in kernel launch configuration

* example fixes

* add async/sync interface comparison benchmark

* fix linting

* reformat for yapf0.29

* fix conflicts of yapf and flake8

* flake 8 is prior than yapf

* Fix simple_test for base and fast_rcnn detector

* Add test of detector forward methods

* Revert forward_test change and add docs indicating expected inputs for forward

* fix linter

* Add tests for NMS

* Fix linting errors

* Add DeviceGaurd to nms_cuda

* test that all configs can be loaded

* Use in_channels correctly in anchor_head and guided_anchor_head

* Fix lint errors. Only tests a subset of configs

* remove local config

* fix yapf

* Remove slower tests

* Remove debug code

* trigger travis

* Enable doctests in CI with xdoctest

* use xdoctest in travis file

* Fix doctest warnings

* dont test eggs directory

* Ensure xdoctest is installed before running CI

* add testing in Travis

* add proj. requirements

* install CUDA

* def tested packages

* add missing meta in setup

* add empty test

* restructure travis tests

* add sample doctest

* switch to nose2

* add sample test

* using pytest

* minor fixes