Replace `funkit` with `annomath`
Move test generator to a separate module
Define entry point for the module
Eliminate global and `_amount`

`_amount` started to feel like a hack so eliminated it. Amount of tests
to run should be passed explicitly instead.
Let `amount` to default as one

Now `amount` doesn't have to be necessarily passed for something to
happen.
Tidy up
Expose `generate` through library index
Tidy up
Annotate `generate`
0.4.0