fix sql, change test to fit my local database, fixed #46

```
var LIST_BY_AUTHOR_SQL = 'SELECT name, package FROM module WHERE id IN\
                          (SELECT module_id FROM tag WHERE tag="latest" AND name IN\
                          (SELECT distinct(name) FROM module WHERE author = ?))';

var LIST_SINCE_SQL = 'SELECT name, package FROM module WHERE id IN\
                      (SELECT module_id FROM tag WHERE tag="latest" AND name IN\
                      (SELECT distinct(name) FROM module WHERE gmt_modified > ?))\
                      ORDER BY name';
```