Declarative over imperative assertions

I found it difficult following along with what the assertions were about. This is an attempt to tackle that using:

- a verbose test api
- removing magic number from assertions

What do you think @lee-jon does this improve or hamper readability?
It was a good refactoring aid to remove relliance on specific number assertions, but I agree this should be taken out now, it just represents a positive integer. 

We wouldn't want a test suite that has the opportunity to hide edge cases via it's randomness - was that your thinking too?