[FIX] make in-memory sqlite work

problem: knex would lose its sqlite3 database connection after 30 secs
which would cause sqlite3 to remove the in-memory database and create
a new fresh one once a new connection was established

reason: knex uses generic-pool-redux package as its pool manager
which has a default timeout of 30secs. It can keep a pool of 1 connection
and not refresh idles, but there's a bug in the option logic that won't
allow a pool with min and max set to 1

solution: have generic-pool-redux fix this logic
for now we'll keep this dirty hack and pin the knex version