Fixed an issue with default lifetime & added some tests for that

[sparshev]

A small fix for not properly working lifetime in fish node configuration - also added a couple of tests to ensure it will work properly & label lifetime will override the default one.

Related Issue

Caused by: #39

How Has This Been Tested?

Automatically

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.