Skip coverage on Java 9.

.travis.yml

@@ -33,4 +33,4 @@ install: /bin/true
 
 script:
   - mvn package -Dskip.unit.tests=true -Dmaven.javadoc.skip=true -V -B
-  - mvn test coveralls:report -V -P coverage
+  - mvn test coveralls:report -V -Dcoveralls

pom.xml

@@ -41,7 +41,6 @@
       <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
       <sureFireOptions9></sureFireOptions9>
       <sureFireForks9>false</sureFireForks9>
-      <coverallsSkip9>false</coverallsSkip9>
 
       <felix.bundle.plugin.version>3.3.0</felix.bundle.plugin.version>
       <felix.version>5.6.2</felix.version>
@@ -441,6 +440,12 @@
 
       <profile>
          <id>coverage</id>
+         <activation>
+            <jdk>1.8</jdk>
+            <property>
+               <name>coveralls</name>
+            </property>
+         </activation>
          <build>
             <plugins>
                <plugin>
@@ -455,9 +460,6 @@
                            <goal>jacoco</goal>
                         </goals>
                         <inherited>false</inherited>
-                        <configuration>
-                           <coveralls.skip>${coverallsSkip9}</coveralls.skip>
-                        </configuration>
                      </execution>
                   </executions>
                </plugin>