Replace Knex.js with SQL building and db connection

[blakeembrey]

Found https://github.com/vitaly-t/pg-promise and https://github.com/hiddentao/squel, can probably use it instead of Knex for a more consistent API usage - I've run into too many type issues.

[vitaly-t]

How is it going so far? :) You may find that pg-promise has powerful enough query formatting that no extra tools needed. And of you think of a case you don't know how to implement using just pg-promise - just ask ;)

[blakeembrey]

@vitaly-t I haven't been able to start yet, still an idea I want to follow up on. I'll let you know if anything pops up.