Parsing plain text files requires more processing than
structured file types like YAML / JSON.
YAML support is built-into ruby > 1.9.3.
The YAML module can easily load a JSON file too.

Why was the year field removed?
Birthdays are recurring. You need to wish people every year.
Why would you want to torment people with the notion of them getting old? 😜

because that is what it is - an example / placeholder configuration file

Supports multiple birthdays from arrays.
Earlier version sent multiple wishes for multiple birthdays,
this version appends the users to a single array
and sends out a single birthday wish message.

You can now configure the birthday database
with your team memebers' usernames or real names.
The bot will mention the users based on this parameter.

The YAML module parses keys with a leading 0 as octcal digits,
invalidating 08 and 09. Parsing them as strings would be safer

HTTParty is the only gem dependency of the bot.
I thought it was redundant to maintain a single
dependency especially when it was achievable with
the standard net/http library except that it would
some extra lines of code.
I thought the extra lines of code was worth it
rather than having to maintain a single dependency.