heroku run rake db:migrate でエラーが起きる！

Question

前提・実現したいこと

railsアプリケーションをherokuでデプライしようとしています。

発生している問題・エラーメッセージ

Running rake db:migrate on ⬢ guarded-sands-38572... up, run.5628 (Free)
rake aborted!
LoadError: libruby.so.2.3: cannot open shared object file: No such file or directory - /app/vendor/bundle/ruby/2.3.0/gems/pg-1.0.0/lib/pg_ext.so
/app/vendor/bundle/ruby/2.3.0/gems/pg-1.0.0/lib/pg.rb:4:in require' /app/vendor/bundle/ruby/2.3.0/gems/pg-1.0.0/lib/pg.rb:4:in <top (required)>'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:82:in require' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:82:in block (2 levels) in require'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:77:in each' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:77:in block in require'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:66:in each' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/runtime.rb:66:in require'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler.rb:108:in require' /app/config/application.rb:7:in <top (required)>'
/app/Rakefile:4:in require_relative' /app/Rakefile:4:in <top (required)>'
/app/vendor/bundle/ruby/2.3.0/gems/rake-12.3.1/exe/rake:27:in <top (required)>' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli/exec.rb:74:in load'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli/exec.rb:74:in kernel_load' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli/exec.rb:27:in run'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli.rb:360:in exec' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/vendor/thor/lib/thor/command.rb:27:in run'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/vendor/thor/lib/thor/invocation.rb:126:in invoke_command' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/vendor/thor/lib/thor.rb:369:in dispatch'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli.rb:20:in dispatch' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/vendor/thor/lib/thor/base.rb:444:in start'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/cli.rb:10:in start' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/exe/bundle:30:in block in <top (required)>'
/app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/lib/bundler/friendly_errors.rb:121:in with_friendly_errors' /app/vendor/bundle/ruby/2.3.0/gems/bundler-1.15.2/exe/bundle:22:in <top (required)>'
/app/bin/bundle:3:in load' /app/bin/bundle:3:in <main>'
(See full trace by running task with --trace)

該当のソースコード

試したこと

heroku公式リファレンス（https://devcenter.heroku.com/articles/getting-started-with-rails4）に沿ってミスのないよう勧めました。また他のサイトを参照して実行しても同様にheroku run rake db:migrateで上のエラーと同じものが発生します。

どなたかわかる方いらっしゃいますでしょうか？

heroku run db:migrateで上記のようにエラーが出てしまいます。

補足情報（FW/ツールのバージョンなど）

ruby 2.3.6
rails 5.1.6