Move versions-maven-plugin into an opt in profile

[jonathanaustin]

The other plugins used by qa_parent have the ability for projects to opt in or out by setting a skip property.

However, the versions-maven-plugin does not appear to have the ability to be skipped. If projects do not want to run this plugin they have no way of skipping it.

Moving the versions-maven-plugin into an opt in profile would allow projects to activate this profile or not.

[jonathanaustin]

One trick that can be used to "skip" the plugin is by assigning it to a "null" phase.

<build>
	<plugins>
		<plugin>
			<groupId>org.codehaus.mojo</groupId>
			<artifactId>versions-maven-plugin</artifactId>
			<version>2.8.1</version>
			<executions>
				<execution>
					<id>display-version-updates</id>
					<phase />
				</execution>
			</executions>
		</plugin>
	</plugins>
</build>

Even though this is an option, the version checking can be an expensive process for large projects and is better to opt in via a profile.