Revert "[maven-release-plugin] prepare for next development iteration"

This reverts commit 72b2ffaff2718962f5ae23a577f2c10430cf5ae5.
diff --git a/indexer-cli/pom.xml b/indexer-cli/pom.xml
index 0b4cbd9..2c478e1 100644
--- a/indexer-cli/pom.xml
+++ b/indexer-cli/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>indexer-cli</artifactId>
diff --git a/indexer-core/pom.xml b/indexer-core/pom.xml
index c13e046..a441ca7 100644
--- a/indexer-core/pom.xml
+++ b/indexer-core/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>indexer-core</artifactId>
diff --git a/indexer-examples/indexer-examples-basic/pom.xml b/indexer-examples/indexer-examples-basic/pom.xml
index 9f0b8cc..69015c1 100644
--- a/indexer-examples/indexer-examples-basic/pom.xml
+++ b/indexer-examples/indexer-examples-basic/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer-examples</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>indexer-examples-basic</artifactId>
diff --git a/indexer-examples/indexer-examples-spring/pom.xml b/indexer-examples/indexer-examples-spring/pom.xml
index 969d7aa..13f44d8 100644
--- a/indexer-examples/indexer-examples-spring/pom.xml
+++ b/indexer-examples/indexer-examples-spring/pom.xml
@@ -24,7 +24,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer-examples</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>indexer-examples-spring</artifactId>
diff --git a/indexer-examples/pom.xml b/indexer-examples/pom.xml
index d75f8f7..6b9608e 100644
--- a/indexer-examples/pom.xml
+++ b/indexer-examples/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>maven-indexer-examples</artifactId>
diff --git a/indexer-reader/pom.xml b/indexer-reader/pom.xml
index 04931d7..a6d7aa8 100644
--- a/indexer-reader/pom.xml
+++ b/indexer-reader/pom.xml
@@ -23,7 +23,7 @@
   <parent>
     <groupId>org.apache.maven.indexer</groupId>
     <artifactId>maven-indexer</artifactId>
-    <version>6.0.1-SNAPSHOT</version>
+    <version>6.0.0</version>
   </parent>
 
   <artifactId>indexer-reader</artifactId>
diff --git a/pom.xml b/pom.xml
index 170d4ce..a152902 100644
--- a/pom.xml
+++ b/pom.xml
@@ -28,7 +28,7 @@
 
   <groupId>org.apache.maven.indexer</groupId>
   <artifactId>maven-indexer</artifactId>
-  <version>6.0.1-SNAPSHOT</version>
+  <version>6.0.0</version>
   <packaging>pom</packaging>
 
   <name>Maven-Indexer</name>
@@ -64,7 +64,7 @@
     <connection>scm:git:https://git-wip-us.apache.org/repos/asf/maven-indexer.git</connection>
     <developerConnection>scm:git:https://git-wip-us.apache.org/repos/asf/maven-indexer.git</developerConnection>
     <url>https://github.com/apache/maven-indexer</url>
-    <tag>HEAD</tag>
+    <tag>maven-indexer-6.0.0</tag>
   </scm>
 
   <issueManagement>