Reply with source if users ask for it

[dergigi]

Resolves issue #1.

I introduced a new script which can be executed with yarn reply. The bot will search twitter for unanswered replies which contain the word "source". If there are any, the bot will perform a lookup of the quote source and post a reply in the following form:

Satoshi wrote this on November 11, 2008, in an email to the cryptography mailing list. You can find the full quote, context, and more information here: https://satoshi.nakamotoinstitute.org/emails/cryptography/10/

Added some tests for the lookup and some other things. There could be more thorough testing, maybe I'll get around to write tests for every quote.

I plan to set up a job to execute the reply script every 10 minutes.

[dergigi]

Oh, I also had to move the actual posting of a random quote out of the "root" of the bot, otherwise, it would post a random quote every time it tries to reply to users (every 10 minutes). See commit
8724f67

[dergigi]

Since there is no CI yet (see #4) I will merge this now and see how it goes in the wild.

test and lint do pass:

[ghost]

🍀