Add a script for factoids

[patcon]

Reticketed from edgi-govdata-archiving/overview#125

Options:

• https://github.com/therealklanni/hubot-factoids
• https://github.com/patcon/hubot-factoid
• https://github.com/halkeye/hubot-phrases

[patcon]

Done here: @22142b9b9f845095515136c660bc27211b478917

Chose hubot-factoids, as it had a few nifty features, like search.

[patcon]

Available for testing in #bot-testing