Allow non-query nodes to be turned into strings
Add 'toQuery' to the prototype of all nodes

This allows doing something like this:
`user.join(photos).toQuery().text`
to build just a part of a query.
Use mocha instead of weird 1/2 of tap for tests

I kept having to scroll back several hundered lines when a test
would fail and the output was ridiculously verbose.
Bump version