[server] Adding metadata table to create-db.js

Summary: When a dev runs create-db.js for the first time, we want this metadata table to be created, with db_version 0.

Test Plan:
Ran the SQL query and it worked as intended.

A table called metadata is created, with db_version set to 0.

Reviewers: atul, ashoat

Reviewed By: atul, ashoat

Subscribers: ashoat, palys-swm, Adrian, karol-bisztyga, benschac, boristopalov

Differential Revision: https://phabricator.ashoat.com/D2625