Bump org.apache.maven.plugins:maven-surefire-plugin from 3.5.5 to 3.5.6 (#1059)

Author: dependabot[bot]

api/pom.xml

@@ -187,7 +187,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>3.5.5</version>
+                <version>3.5.6</version>
             </plugin>
 
             <!-- Checks copyright / license headers -->