geOrchestra CAS customizations

This project has been created from the suggested github template.

It contains some customizations to suit with the conventions followed by the geOrchestra project.

geOrchestra customizations

configuration into /etc/georchestra/cas instead of /etc/cas.
not building a runnable artifact, nor including any tomcat or jetty dependencies (see the gradle.properties file)
A basic custom theme named "georchestra" has been generated using ./gradlew generateTheme
... more to come

./gradlew build

Creating the exploded webapp with the following:

$ ./gradlew explodeWarOnly

Then Build a docker image using:

$ docker build -t georchestra/cas:6.3 .

Contrary to upstream, we don't make use of the jib gradle plugin to build the docker image.