Add support for new types

[cosinequanon]

Fixes #56, #60

Tested locally queries, verified from the release notes these are all the types
that were added.

select cast(1 as integer);
select cast(1 as smallint);
select cast(1 as tinyint);
select cast(1 as decimal);

@onurfiliz thoughts on changing tests? I feel like this should just work but you
know the unit tests better than me so I would be happy to update things as you
see fit.

[ghost]

@cosinequanon updated the pull request.

[ghost]

@cosinequanon updated the pull request.

[ghost]

@cosinequanon updated the pull request.

[onurfiliz]

@cosinequanon, I think we need to extend a few test cases to cover these. Feel free to dig those out if you prefer. Otherwise I can extend them later on, we need to do the same for #62 anyhow.

[cosinequanon]

I agree about extending the tests. Let's just merge this and #63 and then follow up on the tests. I'm pretty sure this will work and I'd rather have our code not fail when users try the example on our main page which is a bad experience.