Add IN and NIN support

[ashtonian]

First attempt https://github.com/a8m/rql/pull/10/

The equality fn for the test doesn't like comparing slices because its deep, not sure what we want to do there.

Looking at integration testing next.

[ashtonian]

resolves https://github.com/a8m/rql/issues/8

[ashtonian]

due to how args are handled by sql.query, this needs to be changed a bit.

Currently assuming the parser receives valid rql it produces something like Select * FROM table WHERE id > ? and name IN (?), and args would contain a slice as an argument [5, [1,2]]. .query wants something more like Select * FROM table WHERE id > ? and name IN (?, ?) and args to be flat [5,1,2].

related: https://stackoverflow.com/questions/20271123/how-to-execute-an-in-lookup-in-sql-using-golang/32837541

[ashtonian]

updated to support multiple ? placeholders, added working integration tests, currently could use some clean up and the tests are broken, not sure why.

[jonathanroze]

Any news about this feature ? Thanks

[c84c]

updated to support multiple ? placeholders, added working integration tests, currently could use some clean up and the tests are broken, not sure why.

If you give me access to your fork, I can help you

[ashtonian]

I'll take another stab at this pending review for https://github.com/a8m/rql/pull/49