[EPIC] Improve the unit test coverage

[hrishin]

At present, the unit test coverage is around 25%. It's scary to refactor or change existing code while adding the new feature.
Need to improve the code coverage for essential modules like

• core - https://github.com/fabric8io/fabric8-maven-plugin/tree/master/core
• enricher - https://github.com/fabric8io/fabric8-maven-plugin/tree/master/enricher
• generator - https://github.com/fabric8io/fabric8-maven-plugin/tree/master/generator
• mojo - https://github.com/fabric8io/fabric8-maven-plugin/tree/master/plugin

Tasks:

• Identify the classes to test
• Prepare the test plan
• Implement the unit tests

[stale]

This issue has been automatically marked as stale because it has not had any activity since 90 days. It will be closed if no further activity occurs within 7 days. Thank you for your contributions!

[stale]

This issue has been automatically marked as stale because it has not had any activity since 90 days. It will be closed if no further activity occurs within 7 days. Thank you for your contributions!