The Smallest Circle (#157)

Apologies for the typos in the summary’s code bits. Google G. has
decided it wants to protect a few email addresses from spam, despite
there being no email addresses. (It’s seeing the @ character of the
instance member variables.)

Where you see “…” immediately preceding “@”, realize those dots
should not be there. In one of the three cases (the to_s method),
those dots should be replaced with a left curly brace “{”.

For the future, I’ll send the email directly to the list rather than
going through Google.