A Twitter bot that fetches Forecast.io data and tweets out the current weather with text and emojis
It looks pretty good to me. Just some minor notes:


Not that it's bad or anything, but in Ruby it's not usual to align code.
You can DRY the case block by creating a hash:

emojis_by_icon = {
  'clear-day' =&gt; 'sunny', 
  'clear-night' =&gt; 'milky-way',
  ...
}

emoji_alias = emojis_by_icon.fetch(current_weather.icon, 'sunny')
icon = Emoji.find_by_alias(emoji_alias).raw

tweet = ... With long lines, I prefer to use the String#% interpolation: 

tweet = "Currently it's %{temperature}° &amp; %{summary} %{icon}" % {
  temperature: current_weather.temperature.round, 
  summary: current_weather.summary.downcase,
  icon: icon,
}