Align Plexus ASM version (#134)

As inject got merged PR
#131

But plexus was not yet present. Align it with inject and centralize asm test version.

Author: cstamas

org.eclipse.sisu.inject/pom.xml

@@ -181,7 +181,7 @@
                 <artifactItem>
                   <groupId>org.ow2.asm</groupId>
                   <artifactId>asm</artifactId>
-                  <version>9.7</version>
+                  <version>${asmVersion}</version>
                 </artifactItem>
                 <artifactItem>
                   <groupId>cglib</groupId>
@@ -229,7 +229,7 @@
                 <artifactItem>
                   <groupId>org.ow2.asm</groupId>
                   <artifactId>asm</artifactId>
-                  <version>9.7</version>
+                  <version>${asmVersion}</version>
                 </artifactItem>
                 <artifactItem>
                   <groupId>com.google.inject</groupId>
@@ -277,7 +277,7 @@
                 <artifactItem>
                   <groupId>org.ow2.asm</groupId>
                   <artifactId>asm</artifactId>
-                  <version>9.7</version>
+                  <version>${asmVersion}</version>
                 </artifactItem>
                 <artifactItem>
                   <groupId>com.google.inject</groupId>

org.eclipse.sisu.plexus/pom.xml

@@ -220,7 +220,7 @@
                 <artifactItem>
                   <groupId>org.ow2.asm</groupId>
                   <artifactId>asm</artifactId>
-                  <version>9.5</version>
+                  <version>${asmVersion}</version>
                 </artifactItem>
                 <artifactItem>
                   <groupId>com.google.inject</groupId>
@@ -258,7 +258,7 @@
                 <artifactItem>
                   <groupId>org.ow2.asm</groupId>
                   <artifactId>asm</artifactId>
-                  <version>9.5</version>
+                  <version>${asmVersion}</version>
                 </artifactItem>
                 <artifactItem>
                   <groupId>com.google.inject</groupId>

pom.xml

@@ -129,6 +129,8 @@
     <mavenBuildVersion>3.6.3</mavenBuildVersion>
     <javaBuildVersion>11</javaBuildVersion>
     <mavenPluginToolsVersion>3.13.0</mavenPluginToolsVersion>
+    <!-- Note: this version is used in tests, to update embedded asm use bin/update_asm.sh -->
+    <asmVersion>9.7</asmVersion>
   </properties>
 
   <dependencyManagement>