feat(jans-keycloak-integration): add keycloak scheduler service

[uprightech]

The keycloak scheduler application has for now the reponsibility of syncing keycloak saml clients using data from janssen.
This issue documents how to deploy it as a service , alongside the required dependencies.
Replace references to <jans_version> with the current build version of janssen.
Additional files mentionned in the issue can be found here

Create directory structure.

Create the diretory /opt/kc-scheduler which should contain the following sub directories:

• /opt/kc-scheduler/bin
• /opt/kc-scheduler/conf
• /opt/kc-scheduler/lib
• /opt/kc-scheduler/logs

Transfer files on the system

1. Download and unzip the file https://jenkins.jans.io/maven/io/jans/kc-jans-scheduler/<jans_version>/kc-jans-scheduler-<jans_version>-deps.zip into /opt/kc-scheduler/lib
2. Download the file https://jenkins.jans.io/maven/io/jans/kc-jans-scheduler/<jans_version>/kc-jans-scheduler-<jans_version>.jar and copy it into /opt/kc-scheduler/lib
3. Unzip the jar downloaded in 3 and copy the files config.properties.sample and logback.xml.sample into the /opt/kc-scheduler/conf/ directory. Make sure to remove the .sample extension.
4. Copy the file start.sh uploaded with this issue to /op/kc-scheduler/bin. Make sure it's executable
5. Copy the file kc-scheduler.service uploaded with this issue to /etc/systemd/system. That's the service file

Configuration file setup

Make sure the following values in config.properties.sample (renamed to config.properties) has the following values set

• app.logging.level.root to DEBUG
• app.config-api.url to the jans-config-api endpoint. E.g. https://example.com/jans-config-api
• app.config-api.auth.url to the jans-auth token endpoint url
• app.config-api.auth.client.id and app.config-api.auth.client.secret are the client id and secrets of the kc_scheduler_api client.
• app.config-api.auth.client.scopes is empty for now
• app.config-api.auth.method is set to basic
• app.keycloak-admin.url is set to the keycloak url . e.g. https://example.com/kc
• app.keycloak-admin.realm is set to master
• app.keycloak-admin.username is set to admin
• app.keycloak-admin.password is set to the keycloak admin password
• app.keycloak-admin.client.id is set to admin-cli

[uprightech]

As per discussions on rocket chat with the team , it was decided that the scheduler will be run at regular intervals as a cron job.
A suggested run interval of every 10 minutes every day was suggested too.
Modifications were made to the application to cater for that. It will run , perform it's tasks and then exit gracefully.
This means invoking the script file start.sh at the specified interval. Also this means removing the kc.service as it's no longer necessary.