Upgrade Vitess

[mpchadwick]

Notes to self:

It looks like we can't do sqlparser.Parse() anymore as of v0.19.0 which we do in processor.go

https://github.com/vitessio/vitess/blob/v0.18.0/go/vt/sqlparser/parser.go#L179
https://github.com/vitessio/vitess/blob/v0.19.0/go/vt/sqlparser/parser.go#L152

There may be some other breaking changes, that's what I've found so far.

Also, create_table.go is using github.com/blastrain/vitess-sqlparser/sqlparser instead of vitess.io/vitess/go/vt/sqlparser. I can't remember why they are using different parsers, but it would be good to try to be consistent if possible.