Run fast script linters before heavier analysis

Includes two small scripts: verify-bash.sh for running shellcheck, and
verify-python.sh for running pylint.

.pylint rc files is a default configuration file generated by
pylint 2.3.1, with one change (min-similarity-lines changed
from 4 to 10).

scripts/verify-bash.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# Copyright (c) 2019 Patryk Obara <patryk.obara@gmail.com>
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# This script exists only to easily run shellcheck on all files in the repo.
+# You can pass additional parameters to this script itself, e.g.:
+#
+# $ ./verify-bash.sh --format=json
+
+run_shellcheck () {
+	git ls-files \
+		| xargs file \
+		| grep "Bourne-Again shell script" \
+		| cut -d ':' -f 1 \
+		| xargs -L 1000 shellcheck "$@"
+}
+
+shellcheck --version
+run_shellcheck "$@"