Sequelize instead of raw SQL

```bash
  326 passing (1m)
  2 pending

=============================================================================
Writing coverage object [/Users/mk2/git/cnpmjs.org/coverage/coverage.json]
Writing coverage reports at [/Users/mk2/git/cnpmjs.org/coverage]
=============================================================================

=============================== Coverage summary ===============================
Statements   : 88.48% ( 2673/3021 )
Branches     : 75.14% ( 952/1267 )
Functions    : 88.89% ( 272/306 )
Lines        : 88.48% ( 2673/3021 )
================================================================================
```