Drop Py36, optimize travis

.travis.yml

@@ -4,25 +4,29 @@ os: linux
 jobs:  # matrix:
   include:
       - python: "3.10"
-        env: TOXENV=py310
+        env: TOXENV=check,py310
+        dist: bionic
       - python: "3.9"
         env: TOXENV=py39
       - python: "3.8"
         env: TOXENV=py38
       - python: "3.7"
         env: TOXENV=py37
         dist: xenial
-      - python: "3.6"
-        env: TOXENV=py36
+        before_install:
+          # Fix "AttributeError: 'str' object has no attribute 'name'" on Py37
+          - pip install -U importlib_metadata
+      # - python: "3.6"
+      #   env: TOXENV=py36
       # - python: "3.5"
       #   env: TOXENV=py35
       - python: "3.11-dev"
         env: TOXENV=py310
+        dist: bionic
   allow_failures:
-    - python: "3.10"
-      env: TOXENV=py310
     - python: "3.11-dev"
       env: TOXENV=py311
+      dist: bionic
 install:
   - pip install tox-travis flake8 isort coveralls coverage
 script:

Pipfile

@@ -4,7 +4,7 @@ verify_ssl = true
 name = "pypi"
 
 [dev-packages]
-black = "==21.9b0"
+black = "~=22.6"
 flake8 = "*" #"~=3.5"
 flake8-bugbear = "*" # "~=18.2"
 flake8-quotes = "*" # "~=1.0"