Remvove cobertura plugin to make Krill build with java-11

Change-Id: I3108eeb249645865ff762201f51e7f57cb90b246
diff --git a/pom.xml b/pom.xml
index 3dd6e66..9d6b014 100644
--- a/pom.xml
+++ b/pom.xml
@@ -64,7 +64,6 @@
     <jackson.version>2.13.4</jackson.version>
     <log4j.version>[2.17.2,)</log4j.version>
     <lucene.version>5.0.0</lucene.version>
-    <cobertura.version>2.7</cobertura.version>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
 
@@ -230,22 +229,8 @@
       <artifactId>commons-io</artifactId>
       <version>2.11.0</version>
     </dependency>
-    
-    <!-- https://mvnrepository.com/artifact/org.codehaus.mojo/cobertura-maven-plugin -->
-    <dependency>
-      <groupId>org.codehaus.mojo</groupId>
-      <artifactId>cobertura-maven-plugin</artifactId>
-      <version>${cobertura.version}</version>
-      <scope>test</scope>
-      <exclusions>
-      	<exclusion>
-      		<groupId>com.sun</groupId>
-      		<artifactId>tools</artifactId>
-      	</exclusion>
-      </exclusions>
-    </dependency>
   </dependencies>
-  
+
   <build>
     <sourceDirectory>${basedir}/src/main/java</sourceDirectory>
     <outputDirectory>${basedir}/bin</outputDirectory>
@@ -352,33 +337,6 @@
 	</configuration>
       </plugin>
 
-      <plugin>
-	<groupId>org.codehaus.mojo</groupId>
-	<artifactId>cobertura-maven-plugin</artifactId>
-	<version>${cobertura.version}</version>
-	<configuration>
-	  <formats>
-	    <format>html</format>
-	    <format>xml</format>
-	  </formats>
-	  <check>
-	    <branchRate>70</branchRate>
-	    <lineRate>70</lineRate>
-	    <haltOnFailure>true</haltOnFailure>
-	    <totalBranchRate>70</totalBranchRate>
-	    <totalLineRate>70</totalLineRate>
-	    <packageLineRate>70</packageLineRate>
-	    <packageBranchRate>70</packageBranchRate>
-	  </check>
-	</configuration>
-	<executions>
-	  <execution>
-	    <goals>
-	      <goal>clean</goal>
-	    </goals>
-	  </execution>
-	</executions>
-      </plugin>
     </plugins>
 
     <resources>