Add scripts and tasks to publish docs to github pages

.travis/publish-docs.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+# Copyright 2018 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+if ! [ -z $DEBUG ]; then
+  set -x
+fi
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+if [ "$COMPONENT" != "docs" ]; then
+    echo "This task runs only to publish docs"
+    exit 0
+fi
+
+make -C ${DIR}/.. build-docs
+
+git config --global user.email "travis@travis-ci.com"
+git config --global user.name "Travis Bot"
+
+git clone --branch=gh-pages --depth=1 https://${GH_REF} ${DIR}/gh-pages
+cd ${DIR}/gh-pages
+
+git rm -r .
+
+cp -r ${DIR}/../site/* .
+
+git add .
+git commit -m "Deploy GitHub Pages"
+git push --force --quiet "https://${GH_TOKEN}@${GH_REF}" gh-pages > /dev/null 2>&1