uodate test dependencies (#17)

diff --git a/pom.xml b/pom.xml
index 43cd09d..842e6fa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -507,7 +507,7 @@
     <dependency>
       <groupId>org.apache.maven.plugin-testing</groupId>
       <artifactId>maven-plugin-testing-harness</artifactId>
-      <version>2.0-alpha-1</version>
+      <version>2.1</version>
       <scope>test</scope>
     </dependency>
     <dependency>