Rename data generators from plural to singular

[jariji]

My pet peeve about hypothesis.py is that it uses the plural booleans() to generate a single boolean. I think it is easier to understand that a single draw from a generator generates one instance of the thing. For example

function f(ints)
  sum(ints)
end

f takes a thing called ints which is supposed to be passed a sequence of integers. But Data.Integers() will pass it a single integer. I think this is confusing and it would be easier to understand if the way to generate one integer were Integer() and, if needed, a shortcut to generate multiple integers were Integers().

A counterargument is that it's more natural for map and filter to work on things that are named pural.

[Seelengrab]

The plural is intentional, since any given generator can generate multiple different instances. The plural also helps prevent punning the existing names like Vector, Dict and so on, preventing a situation where someone attempts to do using Supposition.Data: Vector immediately introducing a name clash with Base.