Fix digit/keycap unicode code points

Emoji digits and # are normal ASCII digits followed by COMBINING ENCLOSING KEYCAP (0x20e3). http://www.unicode.org/~scherer/emoji4unicode/20091221/emojidata.html
Convert emoji names to unicode and vice versa. Add some *gasp* tests. h/t @mbillard
Tests to ensure the gem is in good shape. Leave the unicode tests intentionally failing. Fix to follow.
Merge branch 'keycaps' of git://github.com/lautis/gemoji into unicode-mapping
Fix incorrect codepoint for :stars:
Add missing :night_with_stars:
Compare our emoji to emoji straight from the horse's mouth
Add support for the unicode variation selector (fe0f) added to 107 emojis in iOS 7 / OS X 10.9.

http://www.unicode.org/L2/L2011/11438-emoji-var.pdf
http://unicode.org/reports/tr28/tr28-3.html#13_7_variation_selectors
Add missing train emoji
Fix up incorrect/mising speaker emojis
Make mappings private pending better names
Merge pull request #37 from github/unicode-mapping

Unicode mapping, codepoint fixes, and tests!