ci: add staticcheck to linting

See #6

.gitlab-ci/check_linting.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+echo "### Running gofmt..."
+files="$(gofmt -l .)"
+
+if [ !  -z "$files" ]; then
+	# run gofmt to print out the diff of what needs to be changed
+	gofmt -d -e .
+	exit 1
+fi
+
+echo "### Running staticcheck..."
+staticcheck ./...