Move "@glennsl/bs-jest", "bs-jest-date-mock" to dev dependencies

[JasoonS]

I was getting these 2 errors when I tried to use this package:

File "bsconfig.json", line 1
Error: package @glennsl/bs-jest not found or built
- Did you install it?
- If you did, did you run `bsb -make-world`?

and

File "bsconfig.json", line 1
Error: package bs-jest-date-mock not found or built
- Did you install it?
- If you did, did you run `bsb -make-world`?

Fix is self explanatory I think :)

[mikaello]

Thanks for the fix! 😊 Published v1.0.3 with this fix

[JasoonS]

Thanks for publishing :)