Revert "remove unused plexus dependency"

This reverts commit 5097ceefd24fc83e005bdfa4e254975b025733ad.
diff --git a/pom.xml b/pom.xml
index 0a75ed0..7516b15 100644
--- a/pom.xml
+++ b/pom.xml
@@ -113,6 +113,12 @@
     </dependency>
     <dependency>
       <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-container-default</artifactId>
+      <version>2.1.0</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-utils</artifactId>
       <version>3.3.0</version>
       <scope>test</scope>