Change to Apache artifacts when they are released to Maven Central

[stnor]

The project uses the Penn State Uni artifacts for now.
Change to apache-directory ones as they are released.

        <dependency>
            <groupId>edu.psu.swe.scim</groupId>
            <artifactId>scim-spec-schema</artifactId>
            <version>2.22.4</version>
        </dependency>
        <dependency>
            <groupId>edu.psu.swe.scim</groupId>
            <artifactId>scim-spec-protocol</artifactId>
            <version>2.22.4</version>
        </dependency>
        <dependency>
            <groupId>edu.psu.swe.scim</groupId>
            <artifactId>scim-common</artifactId>
            <version>2.22.4</version>
        </dependency>