py-requests-mock: updated to 1.4.0

1.4.0
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* allow an adapter to be passed to a Mocker object
* Rename [wheel] section to [bdist\_wheel] as the former is legacy
* Include license file in the generated wheel package
* Add testing for newer Python versions 3.5 and 3.6
* Return a separate copy for each call to decorator
* Add string representation to \_RequestObjectProxy

(adam)