Linted code using isort + autoflake + black, fixed wrong use of Optional[bool]

scripts/lint.sh

@@ -0,0 +1,14 @@
+#!/bin/sh -e
+
+export SOURCE="mvt tests"
+
+export PREFIX=""
+if [ -d 'venv' ] ; then
+    export PREFIX="venv/bin/"
+fi
+
+set -x
+
+${PREFIX}autoflake --in-place --recursive --exclude venv ${SOURCE}
+${PREFIX}isort ${SOURCE}
+${PREFIX}black --exclude venv ${SOURCE}