Make Config#template, #makefile
Make aoj.rb site_base.rb
Build SiteBase
Extract ext_to_language_name to Helper module
Implement AOJ
Store local config
Make SampleSite
Change cucumber file names
Rewrite cucumber to fit into SampleSite
Implement Config#get
Implement Config#asset
Implement open_submission
Fix judge bug
User can read description in markdown format
Use splat on Config#get
Merge branch 'feature/site_extensible' into develop

* feature/site_extensible:
  Use splat on Config#get
  User can read description in markdown format
  Fix judge bug
  Implement open_submission
  Implement Config#asset
  Implement Config#get
  Rewrite cucumber to fit into SampleSite
  Change cucumber file names
  Make SampleSite
  Store local config
  Implement AOJ
  Extract ext_to_language_name to Helper module
  Build SiteBase
  Make aoj.rb site_base.rb
  Make Config#template, #makefile
Add a command to add test cases
Add description_xpath to AOJ
User can see diff of wrong outputs
Fix AOJ