Updates to support isort 5.0 (#70)

Removed `not_skip` and `recursive` from `tox.ini` to fix
TypeError: __init__() got an unexpected keyword argument 'not_skip'

* recursive
Prior to version 5.0.0, isort wouldn't automatically traverse directories. The --recursive option was necessary to tell it to do so. In 5.0.0 directories are automatically traversed for all Python files, and as such this option is no longer necessary and should simply be removed.

* not_skip
In an earlier version isort had a default skip of __init__.py. To get around that many projects wanted a way to not skip __init__.py or any other files that were automatically skipped in the future by isort. isort no longer has any default skips, so if the value here is __init__.py you can simply remove the setting.

https://timothycrosley.github.io/isort/docs/upgrade_guides/5.0.0/

* Add python_requires to setup.py

* Remove six from isort standard libraries

isort seems to have switched to `frozenset` for `known_standard_library`, which broke the way we're overriding it here to add `six`. This caused only `six` to be recognized as a standard library, and everything else as third-party. This is an explicit behavior change (see PyCQA/isort#1238).

We no longer use `six` so we can remove this setting

* Remove known_future_library line in isort config in tox.ini

flags/jinja2tags.py

@@ -1,7 +1,8 @@
-from flags.templatetags.feature_flags import flag_disabled, flag_enabled
 from jinja2 import contextfunction
 from jinja2.ext import Extension
 
+from flags.templatetags.feature_flags import flag_disabled, flag_enabled
+
 
 class FlagsExtension(Extension):
     def __init__(self, environment):

flags/panels.py

@@ -3,6 +3,7 @@
 from django.utils.translation import gettext_lazy as _
 
 from debug_toolbar.panels import Panel
+
 from flags import state
 from flags.sources import get_flags
 

flags/state.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import
-
 from django.apps import apps
 from django.core.exceptions import AppRegistryNotReady
 

flags/tests/test_panels.py

@@ -2,6 +2,7 @@
 from django.test import RequestFactory, TestCase, override_settings
 
 from debug_toolbar.toolbar import DebugToolbar
+
 from flags.state import flag_state
 
 

setup.py

@@ -1,8 +1,6 @@
 from setuptools import find_packages, setup
 
 
-long_description = open("README.md", "r").read()
-
 install_requires = ["Django>=1.11,<3.1"]
 
 testing_extras = [
@@ -23,12 +21,13 @@
     author="CFPB",
     author_email="tech@cfpb.gov",
     description="Feature flags for Django projects",
-    long_description=long_description,
+    long_description=open("README.md", "r", encoding="utf-8").read(),
     long_description_content_type="text/markdown",
     license="CC0",
     version="5.0.0",
     include_package_data=True,
     packages=find_packages(),
+    python_requires=">=3.6",
     install_requires=install_requires,
     extras_require={"testing": testing_extras, "docs": docs_extras},
     classifiers=[
@@ -39,8 +38,5 @@
         "License :: Public Domain",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.6",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
     ],
 )

tox.ini

@@ -28,7 +28,7 @@ deps=
 commands=
     black --check flags setup.py
     flake8 flags setup.py
-    isort --check-only --diff --recursive flags
+    isort --check-only --diff flags
 
 [testenv:docs]
 basepython=python3.6
@@ -52,9 +52,7 @@ lines_after_imports=2
 include_trailing_comma=1
 multi_line_output=3
 skip=.tox,migrations
-not_skip=__init__.py
 use_parentheses=1
 known_django=django
-known_future_library=future,six
 default_section=THIRDPARTY
 sections=FUTURE,STDLIB,DJANGO,THIRDPARTY,FIRSTPARTY,LOCALFOLDER