Implement release/deployment workflow

This change adds the necessary bits to the pom.xml file for enabling automated release deployment to the Central Repository from the command line with "mvn deploy". The change uses maven-gpg-plugin to automate the artifact signing, and nexus-staging-maven-plugin to do the actual release deployment steps. Fixes #1

Author: sideshowbarker

pom.xml

@@ -58,7 +58,18 @@ SOFTWARE.
  <tag>HEAD</tag>
  <connection>scm:git:ssh://git@github.com:validator/maven-plugin.git</connection>
  <developerConnection>scm:git:ssh://git@github.com:validator/maven-plugin.git</developerConnection>
+ <url>https://github.com/validator/maven-plugin</url>
  </scm>
+ <distributionManagement>
+ <snapshotRepository>
+ <id>ossrh</id>
+ <url>https://oss.sonatype.org/content/repositories/snapshots/</url>
+ </snapshotRepository>
+ <repository>
+ <id>ossrh</id>
+ <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
+ </repository>
+ </distributionManagement>
 
  <build>
  <plugins>
@@ -110,6 +121,31 @@ SOFTWARE.
  </execution>
  </executions>
  </plugin>
+ <plugin>
+ <groupId>org.sonatype.plugins</groupId>
+ <artifactId>nexus-staging-maven-plugin</artifactId>
+ <version>1.5.1</version>
+ <executions>
+ <execution>
+ <id>default-deploy</id>
+ <phase>deploy</phase>
+ <goals>
+ <goal>deploy</goal>
+ </goals>
+ </execution>
+ </executions>
+ <configuration>
+ <serverId>ossrh</serverId>
+ <extensions>true</extensions>
+ <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+ <autoReleaseAfterClose>true</autoReleaseAfterClose>
+ </configuration>
+ </plugin>
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-gpg-plugin</artifactId>
+ <version>1.6</version>
+ </plugin>
  </plugins>
  <resources>
  <resource>
@@ -188,6 +224,10 @@ SOFTWARE.
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-javadoc-plugin</artifactId>
  <version>2.10.4</version>
+ <configuration>
+ <additionalparam>-Xdoclint:none</additionalparam>
+ <source>8</source>
+ </configuration>
  <executions>
  <execution>
  <id>attach-javadocs</id>
@@ -213,6 +253,12 @@ SOFTWARE.
  </plugin>
  </plugins>
  </build>
+ <activation>
+ <activeByDefault>true</activeByDefault>
+ </activation>
+ <properties>
+ <gpg.executable>gpg</gpg.executable>
+ </properties>
  </profile>
  </profiles>
 </project>