Add Spring Data MongoDB using the Spring Boot Starter to the Spring Boot application classpath.

Experiment with adding SD for Apache Geode's @Region mapping annotation as well as SD MongoDB's @Document mapping annotation and the effects on Spring Boot's auto-configuration support for SD Repositories when multiple data store providers are on the Spring Boot application classpath.

Resolves gh-51.

spring-geode-tests/smoke-tests/multi-store/src/main/java/example/app/model/Contact.java

@@ -37,6 +37,8 @@ import lombok.ToString;
  */
 @Data
 @Entity
+//@Document
+//@Region("Contacts")
 @Table(name = "Contacts")
 @ToString(of = "name")
 @EqualsAndHashCode(of = "name")

spring-geode-tests/smoke-tests/multi-store/src/main/java/example/app/repo/ContactRepository.java

@@ -28,6 +28,7 @@ import example.app.model.Contact;
  * @see example.app.model.Contact
  * @since 1.2.0
  */
+//public interface ContactRepository extends JpaRepository<Contact, String> {
 public interface ContactRepository extends CrudRepository<Contact, String> {
 
 }