Light housekeeping and fix up CI (#190)

* Bump up minimum Python to 3.8 in CI

* Bump up lint tools

Author: reivilibre

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
       matrix:
         # Run the unit tests both against our oldest supported Python version
         # and the newest stable.
-        python_version: [ "3.7", "3.x" ]
+        python_version: [ "3.8", "3.x" ]
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-python@v2

setup.cfg

@@ -27,12 +27,12 @@ dev =
   ldaptor
 
   # for type checking
-  mypy == 0.910
+  mypy == 1.9.0
   types-setuptools
 
   # for linting
   black == 22.3.0
-  flake8 == 4.0.1
+  flake8 == 7.0.0
   isort == 5.9.3
 
 [flake8]