Make decode regex work with codes that have dashes in them

lib/rumoji.rb

@@ -14,7 +14,7 @@ module Rumoji
 
   # Transform a cheat-sheet code into an Emoji
   def decode(str)
-    str.gsub(/:(\S?\w+):/) {|sym| Emoji.find($1.intern).to_s }
+    str.gsub(/:(\S?[\w-]+):/) {|sym| Emoji.find($1.intern).to_s }
   end
 
   def encode_io(readable, writeable=StringIO.new(""))

spec/rumoji_spec.rb

@@ -9,6 +9,7 @@ describe Rumoji do
     @smile = "😄"
     @zero = "0⃣"
     @us = "🇺🇸"
+    @non_potable_water = "🚱"
   end
 
   describe "#encode" do
@@ -22,6 +23,10 @@ describe Rumoji do
     it "transforms a cheat-sheet code into an emoji" do
       Rumoji.decode(":poop:").must_equal @poop
     end
+
+    it "transforms a cheat-sheet code with a dash into an emoji" do
+      Rumoji.decode(":non-potable_water:").must_equal @non_potable_water
+    end
   end
 
   describe "#encode_io" do