fix(scopes): use all instead of runSql in switchDatabase
fix(scopes): use all instead of runSql in switchDatabase

Using runSql resulted in not changing the databases, which in turn leads to an
undefined behavior and broke the --dry-run flag when using scopes which change the
current database.

fixes https://github.com/db-migrate/node-db-migrate/issues/377
fixes #5

db-migrate/mysql,db-migrate/mysql