Update .gitignore.

.gitignore

@@ -3,31 +3,14 @@
 config/database.yml
 config/danbooru_local_config.rb
 config/deploy/*.rb
-config/application.yml
 config/newrelic.yml
-db/*.sqlite3
 log/*.log
 tmp/*
 public/data
-public/assets
-vendor/cache/*.gem
-.sass-cache
-.DS_Store
 coverage
-*~
-*.swp
-tmp/*.jpg
-tmp/*.png
-danbooru.db
-iqdb.db
-danbooru.sublime-project
-danbooru.sublime-workspace
-script/scratch.*
-test/fixtures/vcr_cassettes
 .gitconfig
 test/reports
-/public/packs-test
+public/packs-test
-/node_modules
+public/packs
-yarn-debug.log*
+node_modules
 .yarn-integrity
-public/packs