HADOOP-18417. Upgrade to M7 of surefire plugin (#4795)

This addresses an issue where the plugin's default classpath for executing tests fails to include org.junit.platform.launcher.core.LauncherFactory.

Contributed by: Steve Vaughan Jr

hadoop-project/pom.xml

@@ -167,7 +167,7 @@
 
     <!-- Plugin versions and config -->
     <maven-surefire-plugin.argLine>-Xmx2048m -XX:+HeapDumpOnOutOfMemoryError</maven-surefire-plugin.argLine>
-    <maven-surefire-plugin.version>3.0.0-M1</maven-surefire-plugin.version>
+    <maven-surefire-plugin.version>3.0.0-M7</maven-surefire-plugin.version>
     <maven-surefire-report-plugin.version>${maven-surefire-plugin.version}</maven-surefire-report-plugin.version>
     <maven-failsafe-plugin.version>${maven-surefire-plugin.version}</maven-failsafe-plugin.version>