trivial: optimised jacoco configuration
diff --git a/pom.xml b/pom.xml
index 1658fe0..3070673 100644
--- a/pom.xml
+++ b/pom.xml
@@ -53,7 +53,6 @@
             12343846,12344079,12344332,12344876,12345571</site.jira.version.id>
         <maven.version>3.3.9</maven.version>
         <maven.site.path>${project.artifactId}-archives/${project.artifactId}-LATEST</maven.site.path>
-        <jacoco.version>0.8.3</jacoco.version>
         <sightly.runtime.version>1.1.1-1.4.0-SNAPSHOT</sightly.runtime.version>
         <sightly.compiler.version>1.2.0-1.4.0-SNAPSHOT</sightly.compiler.version>
         <sightly.compiler.java.version>1.1.3-1.4.0-SNAPSHOT</sightly.compiler.java.version>
@@ -177,12 +176,6 @@
             <artifactId>slf4j-simple</artifactId>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.jacoco</groupId>
-            <artifactId>org.jacoco.agent</artifactId>
-            <version>${jacoco.version}</version>
-            <scope>test</scope>
-        </dependency>
     </dependencies>
 
     <build>
@@ -263,63 +256,60 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
             </plugin>
-            <plugin>
-                <groupId>org.jacoco</groupId>
-                <artifactId>jacoco-maven-plugin</artifactId>
-                <version>${jacoco.version}</version>
-                <executions>
-                    <execution>
-                        <id>default-prepare-agent</id>
-                        <goals>
-                            <goal>prepare-agent</goal>
-                        </goals>
-                    </execution>
-                    <execution>
-                        <id>check-coverage</id>
-                        <goals>
-                            <goal>check</goal>
-                        </goals>
-                        <configuration>
-                            <haltOnFailure>true</haltOnFailure>
-                            <rules>
-                                <rule>
-                                    <element>BUNDLE</element>
-                                    <limits>
-                                        <limit>
-                                            <counter>INSTRUCTION</counter>
-                                            <value>COVEREDRATIO</value>
-                                            <minimum>0.80</minimum>
-                                        </limit>
-                                    </limits>
-                                </rule>
-                                <rule>
-                                    <element>CLASS</element>
-                                    <limits>
-                                        <limit>
-                                            <counter>INSTRUCTION</counter>
-                                            <value>COVEREDRATIO</value>
-                                            <minimum>0.80</minimum>
-                                        </limit>
-                                    </limits>
-                                </rule>
-                            </rules>
-                            <excludes>
-                                <exclude>org/apache/sling/maven/htl/HelpMojo.class</exclude>
-                            </excludes>
-                        </configuration>
-                    </execution>
-                    <execution>
-                        <id>report</id>
-                        <phase>prepare-package</phase>
-                        <goals>
-                            <goal>report</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
         </plugins>
     </build>
 
+    <profiles>
+        <profile>
+            <id>jacoco-report</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.jacoco</groupId>
+                        <artifactId>jacoco-maven-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <id>check-coverage</id>
+                                <goals>
+                                    <goal>check</goal>
+                                </goals>
+                                <configuration>
+                                    <dataFile>${project.build.directory}/jacoco-merged.exec</dataFile>
+                                    <haltOnFailure>true</haltOnFailure>
+                                    <rules>
+                                        <rule>
+                                            <element>BUNDLE</element>
+                                            <limits>
+                                                <limit>
+                                                    <counter>INSTRUCTION</counter>
+                                                    <value>COVEREDRATIO</value>
+                                                    <minimum>0.80</minimum>
+                                                </limit>
+                                            </limits>
+                                        </rule>
+                                        <rule>
+                                            <element>CLASS</element>
+                                            <limits>
+                                                <limit>
+                                                    <counter>INSTRUCTION</counter>
+                                                    <value>COVEREDRATIO</value>
+                                                    <minimum>0.80</minimum>
+                                                </limit>
+                                            </limits>
+                                        </rule>
+                                    </rules>
+                                    <excludes>
+                                        <exclude>org/apache/sling/maven/htl/HelpMojo.class</exclude>
+                                    </excludes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
     <reporting>
         <plugins>
             <plugin>