Incrementalify plugin deployments.

.mvn/extensions.xml

@@ -0,0 +1,7 @@
+<extensions xmlns="http://maven.apache.org/EXTENSIONS/1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/EXTENSIONS/1.0.0 http://maven.apache.org/xsd/core-extensions-1.0.0.xsd">
+  <extension>
+    <groupId>io.jenkins.tools.incrementals</groupId>
+    <artifactId>git-changelist-maven-extension</artifactId>
+    <version>1.1</version>
+  </extension>
+</extensions>

.mvn/maven.config

@@ -0,0 +1,2 @@
+-Pconsume-incrementals
+-Pmight-produce-incrementals

pom.xml

@@ -12,11 +12,13 @@
   <groupId>io.jenkins.plugins</groupId>
   <packaging>hpi</packaging>
   <name>Bootstrap 4 API Plugin</name>
-  <version>4.1.3-1-beta3-SNAPSHOT</version>
+  <version>${revision}${changelist}</version>
   <description>Jenkins plug-in that provides Bootstrap 4.</description>
   <url>https://github.com/jenkinsci/bootstrap4-api-plugin</url>
 
   <properties>
+    <revision>4.1.3-1-beta3</revision>
+    <changelist>-SNAPSHOT</changelist>
     <bootstrap.version>4.3.1</bootstrap.version>
     <jquery3-api.version>3.4.1-1-beta1</jquery3-api.version>
     <popper-api.version>1.15.0-1-beta1</popper-api.version>
@@ -490,7 +492,7 @@
     <connection>scm:git:git://github.com/jenkinsci/${project.artifactId}-plugin.git</connection>
     <developerConnection>scm:git:git@github.com:jenkinsci/${project.artifactId}-plugin.git</developerConnection>
     <url>https://github.com/jenkinsci/${project.artifactId}-plugin</url>
-    <tag>HEAD</tag>
+    <tag>${scmTag}</tag>
   </scm>
 
   <repositories>