update environments/production.rb
add environments/staging.rb
add secret_key to devise config
update config/secrets.yml
Add markdown to snippet
style main menu
Add SnippetsController#destroy
add Tag
add Tagable
Add reference beetwen tag and snippet and table
add RailsAdmin:Tag config
hide Tagable in RailsAdmin
Add module SnippetsView#form
add SnippetsView#status
add association from snippets to user
add authenticate_user to SnippetsController
update SnippetsController#edit: add authenticate user
add Snippet#belongs_to?
add login to workflow
refactor SnippetsController#edit