Fixes #69 - Remove patchLevel from config, now in code

Not a big deal, but, to me, this is clearer (i.e., always log the versions regardless, and return early if it is N or N+1; throw anything else).

```
          log.info({
            op: 'MySql.connect',
            patchLevel: mysql.patchLevel,
            patchLevelRequired: patch.level
          })

          if (mysql.patchLevel === patch.level ||
              mysql.patchLevel === patch.level + 1) {
            return mysql
          }

          throw new Error('dbIncorrectPatchLevel')
```