Cleanup Assignment Artifacts

Removed the sample files from oauth2-resource-server that are now
duplicated in the sample project.

This actually cleaned up a problem in the sample project, too, which
was that both data.sql scripts were getting picked up by Spring Data,
causing an integrity constraint. Now with the duplicate file removed,
the workaround has also been removed.

Fixes: gh-9

Author: jzheaux

oauth2/oauth2-resource-server/src/main/resources/application.properties

@@ -1 +1 @@
-insert into message(id, text) values(0, 'Hello World');
+insert into message(id, text) values(1, 'Hello World');