HV-1147 Removing superfluous suite file; only using parallelism on te…

…sts level;

The presence of the suite file suppressed the parallel=methods config.
Removing the file makes the parallel config kick in which made some tests
fail that aren't prepared for parallel execution on the method level. The
same issue would have appeared before when running a single test via
"-Dtest=..." as in that case also the parallel config was applied.

engine/pom.xml

@@ -240,10 +240,7 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <configuration>
-                    <suiteXmlFiles>
-                        <suiteXmlFile>${basedir}/src/test/suite/unit-tests.xml</suiteXmlFile>
-                    </suiteXmlFiles>
-                    <parallel>methods</parallel>
+                    <parallel>tests</parallel>
                     <threadCount>4</threadCount>
                 </configuration>
             </plugin>