ISSUE #464: Add JaCoCo code coverage configuration to master pom.xml

Introduce JaCoCo configuration to the master pom.xml.
JaCoCo handles Java8 syntax better than Cobertura

Author: Enrico Olivelli <eolivelli@apache.org>

Reviewers: Sijie Guo <sijie@apache.org>

This closes #465 from eolivelli/issue-464-jacoco, closes #464

pom.xml

@@ -144,15 +144,16 @@
         <version>4.3.0</version>
       </plugin>
       <plugin>
-        <groupId>org.codehaus.mojo</groupId>
-        <artifactId>cobertura-maven-plugin</artifactId>
-        <version>2.7</version>
-        <configuration>
-         <formats>
-          <format>html</format>
-          <format>xml</format>
-         </formats>
-        </configuration>
+        <groupId>org.jacoco</groupId>
+        <artifactId>jacoco-maven-plugin</artifactId>
+        <version>0.7.9</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>prepare-agent</goal>
+            </goals>
+          </execution>
+        </executions>
       </plugin>
       <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
@@ -172,7 +173,8 @@
         <artifactId>maven-surefire-plugin</artifactId>
         <version>2.19.1</version>
         <configuration>
-          <argLine>-Xmx2G -Djava.net.preferIPv4Stack=true</argLine>
+          <!-- @{argLine} is a variable injected by JaCoCo-->
+          <argLine>@{argLine} -Xmx2G -Djava.net.preferIPv4Stack=true</argLine>
 	  <redirectTestOutputToFile>true</redirectTestOutputToFile>
 	  <reuseForks>false</reuseForks>
 	  <forkedProcessTimeoutInSeconds>1800</forkedProcessTimeoutInSeconds>