Add gh-assets-clone.sh script.

gh-assets-clone.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+# Script to setup the assets clone of the repository using GIT_ASSETS_BRANCH and
+# GIT_API_KEY.
+
+[ -z "$GIT_ASSETS_BRANCH" ] || exit 1
+[ -z "$GIT_API_KEY" ] || exit 1
+
+setup_git() {
+  git config --global user.email "travis@travis-ci.org" || exit 1
+  git config --global user.name "Travis CI" || exit 1
+}
+
+# Constants
+ASSETS_DIR=".assets-branch"
+
+# Clone the assets branch with the correct credentials
+git clone --single-branch -b "$GIT_ASSETS_BRANCH" \
+    "https://${GIT_API_KEY}@github.com/${TRAVIS_REPO_SLUG}.git" "$ASSETS_DIR" || exit 1
+