Format and lint codes and fix packaging (#125)

* add: configure files (setup.py->setup.py+setup.cfg+pyproject.toml)

* add: __download_url__

* format with black and isort

* fix: flake8 section in setup.cfg

* add: E501 to flake ignore

* fix: metadata.name does not accept attr

* fix: merge __version__.py into __init__.py

* fix: flake8 errors in tests/

* fix: datetime.datetime -> datetime

* fix: banner

* fix: ignore W605 for banner

* fix: way to install deps in CI

* add: versem to setuptools

* fix: drop python<=3.6 (#126) from package and CI

tests/test_cdx_utils.py

@@ -1,13 +1,14 @@
 import pytest
-from waybackpy.exceptions import WaybackError
+
 from waybackpy.cdx_utils import (
-    get_total_pages,
+    check_collapses,
+    check_filters,
+    check_match_type,
     full_url,
     get_response,
-    check_filters,
-    check_collapses,
-    check_match_type,
+    get_total_pages,
 )
+from waybackpy.exceptions import WaybackError
 
 
 def test_get_total_pages():
@@ -86,10 +87,10 @@ def test_check_collapses():
 
 
 def test_check_match_type():
-    assert None == check_match_type(None, "url")
+    assert check_match_type(None, "url") is None
     match_type = "exact"
     url = "test_url"
-    assert None == check_match_type(match_type, url)
+    assert check_match_type(match_type, url) is None
 
     url = "has * in it"
     with pytest.raises(WaybackError):