Fix README for uaac changes
[cfid-531] Fix ScimGroupEndpointsTests to run faster

Moved the database setup and tear down logic to static methods that will be called only
once for the entire suite of tests.
[cfid-658] Remove user_id, user_name and email from client tokens

Exclude user-specific attributes from refresh and access tokens for client_credentials
grant.
Fix broken test.
Type-safe YML configuration validation.

Dumps the YAML document into an extra environment property
and uses a YamlConfigurationValidator bean to validate
it later in the application context.

Uses a snakeyaml constructor to bind the YML document
to a configuration Java bean (UaaConfiguration for the UAA).
The bean is annotated with basic JSR303 validation annotations
for additional checking.
Added tests for type-safe config checking.