Many metaclasses in the standard library don't play nice with
__init_subclass__. This bug makes ABCMeta in particular with
__init_subclass__, which is an 80/20 solution for me personally.
AFAICT, a general solution to this problem requires updating all
metaclasses in the standard library to make sure they pass **kwargs to
type.__new__, whereas this PR only fixes ABCMeta. For context, see
https://bugs.python.org/issue29581.

* added a test combining ABCMeta and __init_subclass__
* Added NEWS item

(cherry picked from commit bd583ef9)

* [3.6] bpo-29581: Make ABCMeta.__new__ pass **kwargs to type.__new__ (GH-527)

Many metaclasses in the standard library don't play nice with
__init_subclass__. This bug makes ABCMeta in particular with
__init_subclass__, which is an 80/20 solution for me personally.
AFAICT, a general solution to this problem requires updating all
metaclasses in the standard library to make sure they pass **kwargs to
type.__new__, whereas this PR only fixes ABCMeta. For context, see
https://bugs.python.org/issue29581.

* added a test combining ABCMeta and __init_subclass__
* Added NEWS item.
(cherry picked from commit bd583ef9)

* **kwargs -> ``kwargs`` in attempts to fix the Travis build.

* Quote the **kwargs