Version 22: September 11, 2019 11:22:09 PM

Un-hardcode officer names

- Use site preferences for officer names

- There is no way update the names directly besides using the following line while debugging the app:

    ```
    quip.apps.getSitePreferences().save({officers: {
        president: 'President',
        vpm: 'Vice President of Membership',
        vpe: 'Vice President of Education',
        vppr: 'Vice President of Public Relations',
        secretary: 'Secretary',
        soa: 'Sergeant of Arms',
        treasurer: 'Treasurer',
    }})
    ```

Fixes #12.