add handicap_provider_id to player model - bug 11
add google drive gem  - bug #11

- environment variables for Google drive integration are set per instructions here:

https://devcenter.heroku.com/articles/config-vars

griley@georgermacbook4 (master):leaderboard$ heroku config:set GOOGLE_DRIVE_USER=leaderboard@sapaga.com
Setting config vars and restarting aqueous-taiga-7580... done, v22
GOOGLE_DRIVE_USER: leaderboard@sapaga.com
griley@georgermacbook4 (master):leaderboard$ heroku config:set GOOGLE_DRIVE_PASSWORD=xxxxxxxxxx
Setting config vars and restarting aqueous-taiga-7580... done, v23
GOOGLE_DRIVE_PASSWORD: xxxxxxxxx
rake task to import minimax handicaps via Google spreadsheet - issue #11:resolved