heroku openをするとApplication errorが発生する

###前提・実現したいこと
Herokuに開発中のアプリケーションをアップしたいのですが、heroku openをすると、Application errorの画面が発生してしまいます。
heroku logsで調べても、どこがどうエラーになっているのかがわからないです。
エラーメッセージ
以下、heroku logsです。

Ruby
12017-06-03T10:32:10.844934+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/lazy_load_hooks.rb:43:in `execute_hook'
22017-06-03T10:32:10.844935+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/lazy_load_hooks.rb:52:in `block in run_load_hooks'
32017-06-03T10:32:10.844935+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/lazy_load_hooks.rb:51:in `each'
42017-06-03T10:32:10.844936+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/lazy_load_hooks.rb:51:in `run_load_hooks'
52017-06-03T10:32:10.844936+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/application/finisher.rb:66:in `block in <module:Finisher>'
62017-06-03T10:32:10.844937+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/initializable.rb:30:in `instance_exec'
72017-06-03T10:32:10.844938+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/initializable.rb:30:in `run'
82017-06-03T10:32:10.844939+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:228:in `block in tsort_each'
92017-06-03T10:32:10.844939+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
102017-06-03T10:32:10.844940+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:431:in `each_strongly_connected_component_from'
112017-06-03T10:32:10.844938+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/initializable.rb:59:in `block in run_initializers'
122017-06-03T10:32:10.844940+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:349:in `block in each_strongly_connected_component'
132017-06-03T10:32:10.844943+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each'
142017-06-03T10:32:10.844944+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `call'
152017-06-03T10:32:10.844944+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:347:in `each_strongly_connected_component'
162017-06-03T10:32:10.844945+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:226:in `tsort_each'
172017-06-03T10:32:10.844945+00:00 app[web.1]: 	from /app/vendor/ruby-2.3.4/lib/ruby/2.3.0/tsort.rb:205:in `tsort_each'
182017-06-03T10:32:10.844946+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/application.rb:353:in `initialize!'
192017-06-03T10:32:10.844953+00:00 app[web.1]: 	from /app/config/environment.rb:5:in `<top (required)>'
202017-06-03T10:32:10.844954+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/dependencies.rb:292:in `require'
212017-06-03T10:32:10.844956+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/dependencies.rb:292:in `block in require'
222017-06-03T10:32:10.844956+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/dependencies.rb:258:in `load_dependency'
232017-06-03T10:32:10.844957+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/activesupport-5.1.1/lib/active_support/dependencies.rb:292:in `require'
242017-06-03T10:32:10.844946+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/initializable.rb:58:in `run_initializers'
252017-06-03T10:32:10.844958+00:00 app[web.1]: 	from config.ru:3:in `block in <main>'
262017-06-03T10:32:10.844958+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `instance_eval'
272017-06-03T10:32:10.844958+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:55:in `initialize'
282017-06-03T10:32:10.844960+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `eval'
292017-06-03T10:32:10.844960+00:00 app[web.1]: 	from config.ru:in `<main>'
302017-06-03T10:32:10.844961+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:49:in `new_from_string'
312017-06-03T10:32:10.844962+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/builder.rb:40:in `parse_file'
322017-06-03T10:32:10.844963+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:319:in `build_app_and_options_from_config'
332017-06-03T10:32:10.844959+00:00 app[web.1]: 	from config.ru:in `new'
342017-06-03T10:32:10.844963+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:219:in `app'
352017-06-03T10:32:10.844964+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands/server/server_command.rb:24:in `app'
362017-06-03T10:32:10.844965+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:354:in `wrapped_app'
372017-06-03T10:32:10.844966+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/rack-2.0.3/lib/rack/server.rb:283:in `start'
382017-06-03T10:32:10.844967+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands/server/server_command.rb:131:in `block in perform'
392017-06-03T10:32:10.844969+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands/server/server_command.rb:126:in `tap'
402017-06-03T10:32:10.844967+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands/server/server_command.rb:44:in `start'
412017-06-03T10:32:10.844970+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands/server/server_command.rb:126:in `perform'
422017-06-03T10:32:10.844972+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.19.4/lib/thor/command.rb:27:in `run'
432017-06-03T10:32:10.844976+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/command/base.rb:63:in `perform'
442017-06-03T10:32:10.844977+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/command.rb:44:in `invoke'
452017-06-03T10:32:10.844975+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.19.4/lib/thor.rb:369:in `dispatch'
462017-06-03T10:32:10.844973+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/thor-0.19.4/lib/thor/invocation.rb:126:in `invoke_command'
472017-06-03T10:32:10.844978+00:00 app[web.1]: 	from /app/vendor/bundle/ruby/2.3.0/gems/railties-5.1.1/lib/rails/commands.rb:16:in `<top (required)>'
482017-06-03T10:32:10.844981+00:00 app[web.1]: 	from bin/rails:9:in `<main>'
492017-06-03T10:32:10.844980+00:00 app[web.1]: 	from bin/rails:9:in `require'
502017-06-03T10:32:10.970675+00:00 heroku[web.1]: State changed from starting to crashed
512017-06-03T10:32:12.931070+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=shielded-bayou-76861.herokuapp.com request_id=a61ec723-7d56-46d7-8a61-bc974b0be49d fwd="211.19.111.113" dyno= connect= service= status=503 bytes= protocol=https
522017-06-03T10:32:13.271250+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=shielded-bayou-76861.herokuapp.com request_id=57bbdf76-5376-483e-9618-bd70521b6d38 fwd="211.19.111.113" dyno= connect= service= status=503 bytes= protocol=https