Set timezone environment variable for Jest via global setup rather than by the Windows-incompatible command line statement

[ThomasLatham]

✅ I have read the contributing file

Summary

As documented in #202, the command "TZ=" does not work in Windows (although it does work in MacOS and Linux), so tests would fail in Windows environments on account of an unrecognized command. This PR fixes the problem by instead setting the the timezone environment variable in a global-setup JavaScript file for Jest, thereby making such an action OS independent.

Note: According to the source for this fix, "The normal setupFiles did not work for me, since they run too late (jest: ^23.5.0). So it is mandatory to use the globalSetup file."

[ghost]

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Legend

[PierreBresson]

Thanks @ThomasLatham 🙂🎄

[ThomasLatham]

Glad to be able to help!