[MCLEAN-107] Upgrade to plexus-utils 4.0.0 and plexus-xml 4.0.0 (#26)

diff --git a/pom.xml b/pom.xml
index 03220fc..2e9adc2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -73,9 +73,14 @@
       <scope>provided</scope>
     </dependency>
     <dependency>
-      <groupId>org.apache.maven.shared</groupId>
-      <artifactId>maven-shared-utils</artifactId>
-      <version>3.3.4</version>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-utils</artifactId>
+      <version>4.0.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-xml</artifactId>
+      <version>4.0.0</version>
     </dependency>
 
     <!-- dependencies to annotations -->
diff --git a/src/main/java/org/apache/maven/plugins/clean/Cleaner.java b/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
index 9f5c2fb..97ef594 100644
--- a/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
+++ b/src/main/java/org/apache/maven/plugins/clean/Cleaner.java
@@ -34,7 +34,7 @@
 import org.apache.maven.execution.ExecutionListener;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.plugin.logging.Log;
-import org.apache.maven.shared.utils.Os;
+import org.codehaus.plexus.util.Os;
 import org.eclipse.aether.SessionData;
 
 import static org.apache.maven.plugins.clean.CleanMojo.FAST_MODE_BACKGROUND;
diff --git a/src/main/java/org/apache/maven/plugins/clean/GlobSelector.java b/src/main/java/org/apache/maven/plugins/clean/GlobSelector.java
index 3ba63d7..2d2f99d 100644
--- a/src/main/java/org/apache/maven/plugins/clean/GlobSelector.java
+++ b/src/main/java/org/apache/maven/plugins/clean/GlobSelector.java
@@ -21,8 +21,8 @@
 import java.io.File;
 import java.util.Arrays;
 
-import org.apache.maven.shared.utils.io.DirectoryScanner;
-import org.apache.maven.shared.utils.io.SelectorUtils;
+import org.codehaus.plexus.util.DirectoryScanner;
+import org.codehaus.plexus.util.SelectorUtils;
 
 /**
  * Selects paths based on Ant-like glob patterns.