randRange() only works with int's, but if you use a MAX_INT as the max value, it will overflow the integer and wrap around, giving you a value that is not between the supplied values:
I propose a few tweaks.
Change to use longs instead of integers. I have the need to get random numbers much larger already.
Throw an error if the values are outside of expected ranges and would cause a return value outside of the provided range.
If it is acceptable to do both of these items, I would be happy to make the changes myself and submit a pull request for the code and a test.