capistrano3を使ってRailsAppをデプロイしたいが、「SSHKit::Runner::ExecuteError: 」が出てしまう

##やりたいこと
Rails5で作ったアプリケーションをcapistrano3を用いてAWSにデプロイしたいです。

AWSの初心者です。
Rails5のAppをデプロイしようと以下の記事を参考にして進めております。

###【参考記事】
https://qiita.com/naoki_mochizuki/items/657aca7531b8948d267b
https://qiita.com/shizuma/items/c23518a1934c738ec3b0

そして最後に以下のcapistrano3を使ってデプロイするコマンドを実行までしました。

bundle exec cap production deploy

###エラーlog
(Backtrace restricted to imported tasks)
cap aborted!
SSHKit::Runner::ExecuteError: Exception while executing as (username)@00.000.000.000: bundle exit status: 1
bundle stdout: Nothing written
bundle stderr: master failed to start, check stderr log for details

Caused by:
SSHKit::Command::Failed: bundle exit status: 1
bundle stdout: Nothing written
bundle stderr: master failed to start, check stderr log for details
/Users/(username)/programing/leancanvasmaker/lib/capistrano/tasks/unicorn.rb:11:in block in start_unicorn' /Users/(username)/programing/leancanvasmaker/lib/capistrano/tasks/unicorn.rb:10:in start_unicorn'
/Users/(username)/programing/leancanvasmaker/lib/capistrano/tasks/unicorn.rb:34:in `block (3 levels) in <top (required)>'
Tasks: TOP => unicorn:start
(See full trace by running task with --trace)
The deploy has failed with an error: Exception while executing as (username)@00.000.000.000: bundle exit status: 1
bundle stdout: Nothing written
bundle stderr: master failed to start, check stderr log for details