conf: update pom.xml with working gem related plugins and extensions

pom.xml

@@ -10,9 +10,10 @@
     -->
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <asciidoctorj.version>2.5.2</asciidoctorj.version>
-         <asciidoctorj.diagram.version>2.2.0</asciidoctorj.diagram.version>
-        <jruby.version>9.2.9.0</jruby.version>
+        <asciidoctorj.version>2.5.13</asciidoctorj.version>
+        <asciidoctorj.diagram.version>2.2.0</asciidoctorj.diagram.version>
+        <asciidoctor.maven.plugin.version>3.0.0</asciidoctor.maven.plugin.version>
+        <jruby.version>9.4.6.0</jruby.version>
         <revealjs.version>3.9.2</revealjs.version>
         <!-- Use 'master' as version and remove the 'v' prefixing the download url to use the current snapshot version  -->
         <asciidoctor-revealjs.version>master</asciidoctor-revealjs.version>
@@ -52,16 +53,16 @@
     <build>
         <extensions>
             <extension> <!-- this allows us to download gems -->
-                <groupId>org.torquebox.mojo</groupId>
+                <groupId>org.jruby.maven</groupId>
                 <artifactId>mavengem-wagon</artifactId>
-                <version>1.0.3</version>
+                <version>2.0.2</version>
             </extension>
         </extensions>
         <plugins>
             <plugin>
                 <groupId>com.googlecode.maven-download-plugin</groupId>
                 <artifactId>download-maven-plugin</artifactId>
-                <version>1.6.0</version>
+                <version>1.9.0</version>
                 <executions>
                     <execution>
                         <id>install-revealjs</id>
@@ -79,9 +80,9 @@
                 </executions>
             </plugin>
             <plugin>
-                <groupId>de.saumya.mojo</groupId>
+                <groupId>org.jruby.maven</groupId>
                 <artifactId>gem-maven-plugin</artifactId>
-                <version>1.1.8</version>
+                <version>3.0.3</version>
                 <configuration>
                     <jrubyVersion>${jruby.version}</jrubyVersion>
                     <gemHome>${project.build.directory}/gems</gemHome>
@@ -101,7 +102,7 @@
             <plugin>
                 <groupId>org.asciidoctor</groupId>
                 <artifactId>asciidoctor-maven-plugin</artifactId>
-                <version>2.2.1</version>
+                <version>${asciidoctor.maven.plugin.version}</version>
                 <dependencies>
                     <dependency> 
                         <groupId>org.asciidoctor</groupId>
@@ -141,9 +142,9 @@
                         </goals>
                         <configuration>
                             <sourceDirectory>lectures/asciidoc</sourceDirectory>
-                            <sources>
+                            <!-- sources>
                                 <include>*.adoc</include>
-                            </sources>
+                            </sources -->
                             <resources>
                                 <resource>
                                     <directory>lectures/asciidoc</directory>
@@ -178,9 +179,9 @@
                                 <require>asciidoctor-revealjs</require>
                             </requires>
                             <sourceDirectory>lectures/revealjs</sourceDirectory>
-                            <sources>
+                            <!-- sources>
                                 <include>*.adoc</include>
-                            </sources>
+                            </sources -->
                             <resources>
                                 <resource>
                                     <directory>lectures/revealjs</directory>