Provide xsd configuration for pom files (#143)

it allows to provide completion and validation when editing the files in
most IDEs

Signed-off-by: Aurélien Pupier <[email protected]>

Author: apupier

cassandra/java/pom.xml

@@ -13,7 +13,7 @@
  License for the specific language governing permissions and limitations under
  the License.
 -->
-<project>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <groupId>io.k8s.cassandra</groupId>
     <artifactId>kubernetes-cassandra</artifactId>