DATAGRAPH-1414 - Improve documentation.

Author: meistermeier

src/test/java/org/springframework/data/neo4j/documentation/domain/MovieEntity.java

@@ -18,9 +18,7 @@
 // tag::mapping.annotations[]
 
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 import org.springframework.data.neo4j.core.schema.Id;
 import org.springframework.data.neo4j.core.schema.Node;