Allow changing slowQueryThresholdMs in code

[asvanberg]

Fixes #107

[coveralls]

Pull Request Test Coverage Report for Build 345

• 8 of 8 (100.0%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 50.929%

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Totals
Change from base Build 344:	0.2%
Covered Lines:	521
Relevant Lines:	1023

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💛 - Coveralls