IntegerGenerator without configuration returns only two distinct values

[maxpilotto]

Given this snippet, the result is always 2

val list = mutableListOf<String>()
val gen = IntegerGenerator()

repeat(150) {
    list.add(gen.string())
}

println(list.distinct().size)

This is probably due to the default MAX and MIN values the underlying library uses, this could potentially be fixed by fixing #1