Clean up and enhance archetypes for JUnit and TestNG

[mmerrell-sauce]

The JUnit/TestNG archetypes need some love, care, and documentation.

UPDATE: Instead of "fixing" these archetypes, we're going to create archetypes for our other sample Java frameworks.

A/C:
- Update the README with instructions for how to use the archetypes
- The pom.xml lists the incorrect default artifactId (there's a typo, missing a curly brace)
- Update the default version ID to 1.0.0-SNAPSHOT
- Clean up and bring all Java files into compliance with modern Java practices
- Ensure Codacy report is clean

[mmerrell-sauce]

Actually, after further analysis, these archetypes shouldn't exist. They don't give customers good examples of JUnit and TestNG to follow--we should create archetypes for each of our other Java Sample frameworks, and remove these altogether.