Fix unclosed connection bug

Migrations were opening a client connection without releasing it.  This
means tests would hang at the very least.  It is also why we were forced
to manually exit the migration process.

Author: slifty

src/database/migrate.ts

@@ -8,4 +8,5 @@ export const migrate = async (): Promise<void> => {
     { client },
     path.resolve(__dirname, 'migrations'),
   );
+  client.release();
 };

src/scripts/migrate.ts

@@ -4,7 +4,6 @@ process.stdout.write('Starting migrations...\n');
 migrate()
   .then(() => {
     process.stdout.write('Migrations complete.\n');
-    process.exit();
   })
   .catch((reason: unknown) => {
     process.stdout.write('Migrations failed!\n');