From builtin.go:
The complex built-in function constructs a complex value from two floating-point
values. The real and imaginary parts must be of the same size, either float32 or
float64 (or assignable to them), and the return value will be the corresponding
complex type (complex64 for float32, complex128 for float64).

Co-authored-by: Maxime Guerreiro <mguerreiro@users.noreply.github.com>

* Add test proving charRange.choose excludes the last item

Change charRange#choose to accept an interface, int63nPicker, exposing only
Int63n(int64) int64. This allows the test to pass a custom RNG, returning a
constant value (0 or the last possible int).

Change charRange#choose to act on an immutable copy of charRange.

* Allow charRange.choose to pick the last rune

Before this change, choose would never pick the last character of the set. This
is not the expected behavior: if the range is a-z, we expect a,b,...,y,z to be
picked in a uniform way.

* Add NewFromGoFuzz

Add a helper function that enables using gofuzz (this project) with
go-fuzz (https://github.com/dvyukov/go-fuzz) for continuose
fuzzing. Essentially, it enables translating the fuzzing bytes from
go-fuzz to any Go object using this library.

This change will enable using this project with fuzzing websites such as fuzzit.dev
or fuzzbuzz.io.

The underlying implementation was an idea of lavalamp, by which a random source
is created that generates random numbers from the input bytes slice. In this way
changes in the source result in logical changes in the random data, which enables
the fuzzer to efficiently search the space of inputs.

Fixes #33

* - Optimize the randBool() function.

  Previous time: 15.175 ns/op
  New time:      4.78 ns/op

* - Optimize randString() by using strings.Builder.
  30% less memory used and a 5 to 7% higher throughput.

* - Add benchmarks for randBool() and randString().

* - Ran go fmt

Add UnicodeRange and UnicodeRanges types, to generate strings with a more controllable set of characters. Use is optional.

* Update genShouldFill to use greater-then-or-equal

Because rand.Float64 can return 0 it was possible for this function to 
return false when the nilChance is set to 0 (because 0 > 0 = false).

* Add test case for NilChance(0) against "random" zero