Add command to set and enable deploymentExportPath

[mojavelinux]

Introduce a command that configures the Arquillian engine element in arquillian.xml to export the deployments to a specified folder.

Proposed name: configure-engine
Proposed flag or option name: deploymentExportPath

Example arquillian.xml contents after running the command:

<arquillian xmlns="http://jboss.org/schema/arquillian"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://jboss.org/schema/arquillian
        http://jboss.org/schema/arquillian/arquillian_1_0.xsd">
    <engine>
        <property name="deploymentExportPath">target/deployments</property>
    </engine>
</arquillian>