[ci] Coveralls hasn't built the project since June 25th

The previous fix was not enough. Coveralls maven plugin depends on
javax.xml.bind, which has been removed with JDK11, since it is
a EE feature.

Workaround is now, to add the jaxb-api as a plugin dependency, so
that the utility class javax.xml.bind.DatatypeConverter is
available.

Fixes #1317

.travis/build-coveralls.sh

@@ -12,11 +12,6 @@ if ! travis_isPush; then
     exit 0
 fi
 
-#
-# for java9: enable all modules.
-# coveralls plugin seems to need java.xml.bind module
-echo "MAVEN_OPTS='-Xms1g -Xmx1g --add-modules java.se'" > ${HOME}/.mavenrc
-
 (
     # disable fast fail, exit immediately, in this subshell
     set +e

pom.xml

@@ -965,6 +965,17 @@ Additionally it includes CPD, the copy-paste-detector. CPD finds duplicated code
                         <groupId>org.eluder.coveralls</groupId>
                         <artifactId>coveralls-maven-plugin</artifactId>
                         <version>4.3.0</version>
+                        <dependencies>
+                            <!--
+                                coveralls maven plugin needs javax.xml.bind api
+                                See also https://github.com/trautonen/coveralls-maven-plugin/issues/112
+                            -->
+                            <dependency>
+                                <groupId>javax.xml.bind</groupId>
+                                <artifactId>jaxb-api</artifactId>
+                                <version>2.3.0</version>
+                            </dependency>
+                        </dependencies>
                     </plugin>
                 </plugins>
             </build>