DATACASS-206 - Fix delete using custom column names.

We now use the specified column name from the entity annotation to construct the where clause in a delete statement.

Original pull request: #73.

spring-cql/src/test/resources/logback.xml

@@ -9,6 +9,8 @@
 
 	<logger name="org.springframework" level="ERROR" />
 	<logger name="org.springframework.cassandra" level="ERROR" />
+	<logger name="org.springframework.data.cassandra" level="ERROR" />
+
 	<logger name="com.datastax" level="ERROR" />
 
 	<!-- See https://issues.apache.org/jira/browse/CASSANDRA-8220 -->