.gitlab-ci.yml: check for dco

scripts/check-dco

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+emails=$(git log master..HEAD --pretty=format:'%ae' | sort | uniq)
+for email in $emails; do
+  printf "checking %s\n" "$email"
+  if ! curl -s 'https://dco.commento.io/api/has-signed' -d "email=$email" -X POST \
+         | jq '.hasSigned' \
+         | grep -q true; then
+    printf "%s has not signed the DCO: https://dco.commento.io\n" "$email"
+    exit 1
+  fi
+done