TS: service lifecycles can be arrays

[shawnmcknight]

📝 Description

This PR adjusts the typescript definitions for ServiceSchema to allow the lifecycle events to be typed as arrays.

Note: As there are very few tsd tests in the repo, I am unsure what the expectations are for those types of tests. I did my best to try to create what made sense to me as a test of this change, but will adjust if necessary.

🎯 Relevant issues

Resolves #520

💎 Type of change

• Bug fix (non-breaking change which fixes an issue)

🚦 How Has This Been Tested?

Typescript unit tests created to test both single and array specifications.

🏁 Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have commented my code, particularly in hard-to-understand areas

[coveralls]

Pull Request Test Coverage Report for Build 1822

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 91.959%

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Totals
Change from base Build 1821:	0.01%
Covered Lines:	4840
Relevant Lines:	5027

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 1822

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 91.959%

---

Totals
Change from base Build 1821:	0.01%
Covered Lines:	4840
Relevant Lines:	5027

---

💛 - Coveralls

[icebob]

Good job!