fix(preprocessor) Reset coverageObjRegex before each use

[terussell85]

When using the includeAllSources flag, every other non-tested file is included. This appears to be because the coverageObjRegex is global and shared. Resetting the regex allows files to match correctly when coverageObjRegex.exec() is called.

Likely to help partially resolve #166, if not completely.

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[terussell85]

I signed it!

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CLAs look good, thanks!

[terussell85]

The ESlint issues causing the CI to fail are in files unchanged by this PR. To keep changes in the PR isolated, it seems that the ESlint fixes should be done elsewhere.

[dignifiedquire]

Thanks will merge and release tomorrow.

[dignifiedquire]

Thanks and sorry for the delay. Released as 0.5.2

[djmc]

Thanks!