Added isHalloween.rb (hacktoberfest17#1392)

Author: julianpz21

halloween/isHalloween.rb

@@ -0,0 +1,11 @@
+require 'date'
+
+date = Date.today
+
+if date.mon == 10 and date.day == 31
+  puts "Happy Halloween!"
+elsif date.mon == 10 
+  puts "It's October, but today is not Halloween!"
+else 
+  puts "It's not October"
+end