Use a lightweight tag to change project version

In this example we'll consider quite the same example than inside Introduce jgitver-maven-plugin in existing project except that we expect the version after release 2.4.0 to be 3.0.0-SNAPSHOT (see bottom page for a project example).

Here we'll follow quite the same steps plus an additional one to tell jgitver-maven-plugin that we want 3.0.0-SNAPSHOT to be the current version:

1. go to your project directory

   cd demo3

2. create maven extension file to use jgitver-maven-plugin

   this step just consists in creating a .mvn directory whith an extensions.xml file, see README or use the following command:

   sh -c "$(wget https://raw.githubusercontent.com/jgitver/jgitver-maven-plugin/master/src/doc/scripts/install.sh -O -)"
   

3. let's clarify that you now use jgitver-maven-plugin by forcing the version in POMs to 0

   mvn versions:set -DnewVersion=0 && mvn versions:commit
   

4. let's commit the addition of jgitver-maven-plugin and the new version

   git add .mvn
   git add -u
   git commit -m "introduction of jgitver-maven-plugin, set version to 0"
   

5. use a lightweight tag to define version to 3.0.0-SNAPSHOT

Do not set a comment on the tag, nor use -a or -s or it will become an annotated one.

```
git tag 3.0.0-SNAPSHOT
```

1. you're done

   mvn validate
   
   [INFO] Scanning for projects...
   [INFO] jgitver-maven-plugin is about to change project(s) version(s)
   [INFO]     fr.brouillard.jgitver.demos::demo3::0 -> 3.0.0-SNAPSHOT
   [INFO]                                                                         
   [INFO] ------------------------------------------------------------------------
   [INFO] Building demo3 3.0.0-SNAPSHOT
   [INFO] ------------------------------------------------------------------------
   [INFO] ------------------------------------------------------------------------
   [INFO] BUILD SUCCESS
   [INFO] ------------------------------------------------------------------------
   [INFO] Total time: 0.550 s
   [INFO] Finished at: 2016-12-14T20:56:51+01:00
   [INFO] Final Memory: 8M/198M
   [INFO] ------------------------------------------------------------------------
   

Project example

mvn archetype:generate -B \
  -DarchetypeCatalog=internal \
  -DarchetypeGroupId=org.apache.maven.archetypes \
  -DarchetypeArtifactId=maven-archetype-quickstart \
  -DarchetypeVersion=1.1 \
  -DgroupId=fr.brouillard.jgitver.demos \
  -DartifactId=demo3 \
  -Dpackage=fr.brouillard.jgitver.demos \
  -Dversion=1.0.0-SNAPSHOT

cd demo3
git init
git config user.name "Bob TheBuilder"
git config user.email bobthebuilder@nowhere.com
echo "target/" > .gitignore
echo "Init" > actions
git add .
git commit -m "initial commit"
mvn versions:set -DnewVersion=1.0.0 && mvn versions:commit
git add -u
git commit -m "release 1.0.0"
git tag -m "release 1.0.0" 1.0.0
mvn versions:set -DnewVersion=2.4.0-SNAPSHOT && mvn versions:commit
echo "Some action for 2.4.0-SNAPSHOT" >> actions
git add -u
git commit -m "switch to 2.4.0-SNAPSHOT"
mvn versions:set -DnewVersion=2.4.0 && mvn versions:commit
git add -u
git commit -m "release 2.4.0"
git tag -m "release 2.4.0" 2.4.0
mvn versions:set -DnewVersion=3.0.0-SNAPSHOT && mvn versions:commit
git add -u
git commit -m "switch to 3.0.0-SNAPSHOT"