Deploy mkdocs when merging to master

Only changes to master and PRs starts the travis job.
On PR Maven tests and mkdocs build for warnings and error check is done.
On change on master Maven is **not** run and the documentation is built
and deployed using a deploy key. The encrypted deploy key is not part of
this commit, it needs to be provided by an admin for this repository.

.travis.yml

@@ -4,7 +4,21 @@ install:
 - pip install --user mkdocs mkdocs-material
 script:
 - mvn test -B
-- if [[ "${TRAVIS_PULL_REQUEST}" != "false" ]]; then cd documentation && mkdocs build --clean --verbose --strict && cd ..; fi;
+- |
+  if [[ "${TRAVIS_PULL_REQUEST}" != "false" ]]
+  then
+    cd documentation && mkdocs build --clean --verbose --strict && cd ..
+  else
+    # Only in case we are in master branch of the leading SAP repo we would like to deploy,
+    # not from the forks.
+    if [[ "${TRAVIS_BRANCH}" == "master" && "${TRAVIS_REPO_SLUG}" == "SAP/jenkins-library" ]]
+    then
+       openssl aes-256-cbc -K $encrypted_12c8071d2874_key -iv $encrypted_12c8071d2874_iv -in cfg/id_rsa.enc -out cfg/id_rsa -d
+      ./gh-pages-deploy.sh
+    else
+       echo "Publishing documentation skipped."
+    fi
+  fi
 cache:
   directories:
   - $HOME/.m2

gh-pages-deploy.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+echo "Found change on master: Deployment of documentation"
+
+PRIVATE_KEY="cfg/id_rsa"
+
+chmod 600 "${PRIVATE_KEY}"
+eval `ssh-agent -s`
+ssh-add "${PRIVATE_KEY}"
+git config user.name "Travis CI Publisher"
+git remote add docu "git@github.com:$TRAVIS_REPO_SLUG.git";
+git fetch docu gh-pages:gh-pages
+echo "Pushing to gh-pages of repository $TRAVIS_REPO_SLUG"
+cd $TRAVIS_BUILD_DIR/documentation
+mkdocs gh-deploy -v --clean --remote-name docu