Add "composure" from "https://github.com/erichs/composure@1.3.1"

git-vendor-name: composure
git-vendor-dir: vendor/github.com/erichs/composure
git-vendor-repository: https://github.com/erichs/composure
git-vendor-ref: 1.3.1

vendor/github.com/erichs/composure/test/runshellcheck.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env sh
+
+# run code quality metrics
+echo "Testing \"code quality\" with shellcheck.net in ../composure.sh:"
+datafile=shellcheck.raw
+metricfile=shellcheck.out
+
+curl -s --data-urlencode script="$(cat ../composure.sh)" \
+  www.shellcheck.net/shellcheck.php > $datafile
+cat $datafile | python -mjson.tool > $metricfile
+rm $datafile
+cat $metricfile
+
+# check for shellcheck.net errors
+cat $metricfile | grep -q error
+if [ $? -eq 0 ]; then
+  echo "! shellcheck.net:../composure.sh:0  [ errors ]  FAILED"
+  rm $metricfile
+  exit 2
+fi
+
+# check for shellcheck.net warnings
+cat $metricfile | grep -q warning
+if [ $? -eq 0 ]; then
+  echo "! shellcheck.net:../composure.sh:0  [ warnings ]  FAILED"
+  rm $metricfile
+  exit 2
+fi
+
+echo "! shellcheck.net:../composure.sh:0 [ no errors or warnings ] ok"
+rm $metricfile