Moved APIKEYs to config.js; reworking Word()

THIS IS BROKEN -- saving WIP to repo for retrieval at home
2nd phase of reworking

Added `songSets` and `bots` collections to config.
Simplified `randomFromArray()`
Implemented `getArtistTitlePair`
Renamed some variables for clarity/accuracy
Rough refactoring to call `makeLyrpicTweet()` with a `bot` object

TODO:
Implement initialization (check config for `bots`, call
`setInterval(makeLyrpicTweet(bot),bot.interval)` for each, &c)
Compartmentalize/clean up
Rework `getRhymes` and related functions
3rd phase of reworking

***[CONVERTED TABS TO SPACES]***
Added `Bot` constructor,
Moved some functions to be methods of `Bot`,
Cleaned up `isRhymeInArray` slightly,
Re-ordered code blocks in `lyrpictweet.js`.
Altered `config.js` structure.

TODO:
Clean up `findRhymes`,
Make `makeYQL` generic without chartLyrics baked in,