- renamed the SemverJVersionManager to Semver4jVersionManager as the library is named semver4j

- renamed the Test class accordingly
- made semver4j an optional dependency
- updated javadoc of Semver4jVersionManager to make it clear that the semver4j library must be included

pf4j/pom.xml

 			<groupId>com.vdurmont</groupId>
 			<artifactId>semver4j</artifactId>
 			<version>3.1.0</version>
+			<optional>true</optional>
 		</dependency>
         <dependency>
             <groupId>org.ow2.asm</groupId>

pf4j/src/main/java/org/pf4j/SemverJVersionManager.java → pf4j/src/main/java/org/pf4j/Semver4jVersionManager.java

 
 /**
  * Implementation for {@link VersionManager}.
- * This implementation uses semverJ (a Java implementation of the SemVer Specification).
+ * This implementation uses semver4j (a Java implementation of the SemVer Specification). Before using it you have to include the optional
+ * dependency semver4j
  *
  * @author Wolfram Haussig
  */
-public class SemverJVersionManager implements VersionManager {
+public class Semver4jVersionManager implements VersionManager {
 
     /**
      * the parser type of the version - see https://github.com/vdurmont/semver4j#the-semver-object for details
      * creates a version manager with the given parser type
      * @param type
      */
-    public SemverJVersionManager(SemverType type) {
+    public Semver4jVersionManager(SemverType type) {
         this.type = type;
     }
 
     /**
      * creates a version manager with the NPM parser type which supports ranges
      */
-    public SemverJVersionManager() {
+    public Semver4jVersionManager() {
         this(SemverType.NPM);
     }
 

pf4j/src/test/java/org/pf4j/SemverJVersionManagerTest.java → pf4j/src/test/java/org/pf4j/Semver4jVersionManagerTest.java

 /**
  * @author Wolfram Haussig
  */
-public class SemverJVersionManagerTest {
+public class Semver4jVersionManagerTest {
 
     private VersionManager versionManager;
 
     @BeforeEach
     public void init() {
-        versionManager = new SemverJVersionManager();
+        versionManager = new Semver4jVersionManager();
     }
 
     @Test