Adding KC migration script

See [AGPUSH-1136](https://issues.jboss.org/browse/AGPUSH-1136) for details/background on this PR.

How to test ? 
1. setup WF with MySQL (see https://aerogear.org/docs/unifiedpush/ups_userguide/server-installation/#_mysql_database)
2. deploy (`copy`) the 'auth-server' from 1.0.0.Final (only the auth-server). Get it [here](https://repository.jboss.org/nexus/content/repositories/public/org/jboss/aerogear/unifiedpush/unifiedpush-auth-server/1.0.0.Final/unifiedpush-auth-server-1.0.0.Final.war)
3. Login to http://localhost:8080/auth/admin/aerogear/console/index.html and change the default password
4. Shutdown WF
5. Open a MySQL client of your choice
6. execute the script of this PR
7. copy the auth-server.war file from 1.0.2 release to the `standalone/deployments` folder. Get it [here](https://repository.jboss.org/nexus/content/repositories/public/org/jboss/aerogear/unifiedpush/unifiedpush-auth-server/1.0.2/unifiedpush-auth-server-1.0.2.war)
_*Alternative*_ you can build the `1.0.x` or `master` branch - all have the same bug :-) 
8. start up the WF
9. Login to http://localhost:8080/auth/admin/aerogear/console/index.html 

If that worked, the migration worked for you too