Add gh pages to travis to sync docs

.travis.yml

@@ -1,8 +1,5 @@
 language: java
-before_install: git clone https://github.com/dsyer/spring-security-rsa tmp && (cd tmp && mvn install -DskipTests=true)
-install: mvn install -q -U -DskipTests=true -Dmaven.test.redirectTestOutputToFile=true
+before_install: git config user.name "$GIT_NAME" && git config user.email "$GIT_EMAIL" && git config credential.helper "store --file=.git/credentials" && echo "https://$GH_TOKEN:@github.com" > .git/credentials
+install: mvn install -q -U -DskipTests=true -Dmaven.test.redirectTestOutputToFile=true && ./src/main/asciidoc/ghpages.sh
 script: mvn --settings .settings.xml deploy -nsu -Dmaven.test.redirectTestOutputToFile=true
-env:
-  global:
-  - secure: aomAMudvGhboHcPQDfZ9xFv0ThFMD53aCbX8f9DE0X6GudmdG4fcI02BDfIwFiDG8TG0DZl5brHCzbfgvylNv+Z54GwhzrMytUGv3sn2Meal5bhHm6opjHARqKzNnV8IHRYTVAZbBZK/9eUWIyQtxEL+fmK3PtzlTRshT81hI8I=
-  - secure: YhCHblp6q9FF4kCB4OlvqVpmMjysObdFuioDstRdvCc7V5fpxwnaGlt46qXAEsYbbdAw4YTibFid9vwyGT/cqbmaq5q0l5qrxEbe/sOdM1TTnH4rLIDLdSdhub3J18WWxtHlF4NmhmR3XL0bOIWjNvgoLkPyc6acILn+8FBzC4c=
+

src/main/asciidoc/ghpages.sh

@@ -0,0 +1,46 @@
+#!/bin/bash -x
+
+git remote set-url --push origin `git config remote.origin.url | sed -e 's/^git:/https:/'`
+
+if ! (git remote set-branches --add origin gh-pages && git fetch -q); then
+    echo "No gh-pages, so not syncing"
+    exit 0
+fi
+
+if ! [ -d target/generated-docs ]; then
+    echo "No gh-pages sources in target/generated-docs, so not syncing"
+    exit 0
+fi
+
+# Stash any outstanding changes
+###################################################################
+git diff-index --quiet HEAD
+dirty=$?
+if [ "$dirty" != "0" ]; then git stash; fi
+
+# Switch to gh-pages branch to sync it with master
+###################################################################
+git checkout gh-pages
+
+for f in target/generated-docs/*; do
+    file=${f#target/generated-docs/*}
+    if ! git ls-files -i -o --exclude-standard --directory | grep -q ^$file$; then
+        # Not ignored...
+        cp -rf $f .
+        git add -A $file
+    fi
+done
+
+git commit -a -m "Sync docs from master to gh-pages"
+
+# Uncomment the following push if you want to auto push to
+# the gh-pages branch whenever you commit to master locally.
+# This is a little extreme. Use with care!
+###################################################################
+git push origin gh-pages
+
+# Finally, switch back to the master branch and exit block
+git checkout master
+if [ "$dirty" != "0" ]; then git stash pop; fi
+
+exit 0