.flake8: add flake8 config

.flake8

@@ -0,0 +1,14 @@
+[flake8]
+max-line-length = 127
+max-complexity = 10
+exclude =
+    .git,
+    __pycache__,
+    .pytest_cache,
+    *.pyc,
+    .venv,
+    venv,
+    env,
+    base/,
+    redis_data/,
+    .vagrant/