Bump org.apache.maven.plugins:maven-surefire-plugin from 3.5.5 to 3.5.6 (closes #273)

Bumps [org.apache.maven.plugins:maven-surefire-plugin](https://github.com/apache/maven-surefire) from 3.5.5 to 3.5.6.
- [Release notes](https://github.com/apache/maven-surefire/releases)
- [Commits](https://github.com/apache/maven-surefire/compare/surefire-3.5.5...surefire-3.5.6)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-surefire-plugin
  dependency-version: 3.5.6
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Change-Id: I07a9e2e325a898e68c70c284dc99e8d0f30950be
diff --git a/pom.xml b/pom.xml
index 749652c..7909e8b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -304,7 +304,7 @@
       <plugin>
 	<groupId>org.apache.maven.plugins</groupId>
 	<artifactId>maven-surefire-plugin</artifactId>
-	<version>3.5.5</version>
+	<version>3.5.6</version>
 	<configuration>
           <useSystemClassLoader>false</useSystemClassLoader>
           <argLine>-Xmx512m</argLine>