FIX a typo causing an ERROR log (spec-first#523)

* FIX a typo causing an ERROR log

A small bug was introduced in spec-first#500 when sanitizing the request query
parameters. Instead of fetching the arguments from `request.query`,
the parameters were sanitized from the `request.form`. This causes an
error log to be printed, as the parameters are not expected for the
query (for example in the case of a POST request).

Fixes spec-first#504

* adds a fixture for testing query param sanitazion

Adds a simple fixture to test form and query parameter sanitazion. This
is mostly related to spec-first#522, in which the `formData` parameters were
treated as query parameters.

* add a test to validate form data params

* introduce testfixtures library

Restoring Flask-Injector support by passing "undocumented" path param…

…eters to the handler (spec-first#526)

* Restored Flask-Injector support

* Added a unit test to verify injection works (spec-first#469)

* Changed unittest to support Python 2

Fix UnicodeEncodeError for query-strings on Python 2 (spec-first#507)

* Fix UnicodeEncodeError for query-strings on Python 2

* Fix test for Python 3.4 and 3.5

setup.py: Use env markers for Python version-specific dependencies (s…

…pec-first#495)

* setup.py: Use env markers for Python version-specific dependencies

Changing package properties dynamically in setup.py means that universal
wheels will actually be built only for the builder's environment, and
might not work properly on different platforms/PYthon versions.

Closes spec-first#493

* travis: Upgrade setuptools before running tests

* reqs: Stop installing pathlib from mercurial in dev mode

The mercurial repo is at 0.8 while the latest release on PyPI is 1.0.1

added setup.cfg (spec-first#492)

Split tokeninfo scope if it is a string (spec-first#477)

* Split tokeninfo scope if it is a string

* Add test for string and array scopes

* Fix isort lint error

Flask request user support (spec-first#432)

* ConnexionRequest.context proxied to flask.request instance

* Add type annotations for FlaskRequestContextProxy

* Sort imports

* Sort imports

* Remove unnecessary code