Fix bug.

seminar.gemspec

@@ -1,9 +1,13 @@
 # -*- encoding: utf-8 -*-
 # stub: seminar 0.0.1 ruby lib
+begin
   require "yaml"
   require "erb"
   data = File.open(File.join(File.dirname(__FILE__), 'config', 'list.yml')).read
-$seminar_list = YAML.safe_load(ERB.new(data).result(binding))
+  $seminar_list = YAML.safe_load(ERB.new(data).result(binding)).map{|k,v| [k.to_sym,v]}.to_h
+rescue => e
+  puts [e.to_s,e.backtrace]
+end
 Gem::Specification.new do |s|
   s.name = "seminar"
   s.version = "0.0.1"