rails サーバーが立ち上がらない

レイルズチュートリアルを学習していると、Rails serverが立ち上がらず、苦労しています。

調べても解決しないため、解決策をご教示頂きたく。。

rails s

Could not find gem 'rails (= 5.1.6)' in any of the gem sources listed in your Gemfile.
Run bundle install to install missing gems.

Gem File


source 'https://rubygems.org'

gem 'rails',        '5.1.6'
gem 'puma',         '3.9.1'
gem 'sass-rails',   '5.0.6'
gem 'uglifier',     '3.2.0'
gem 'coffee-rails', '4.2.2'
gem 'jquery-rails', '4.3.1'
gem 'turbolinks',   '5.0.1'
gem 'jbuilder',     '2.7.0'

group :development, :test do
  gem 'sqlite3', '1.3.13'
  gem 'byebug',  '9.0.6', platform: :mri
end

group :development do
  gem 'web-console',           '3.5.1'
  gem 'listen',                '3.1.5'
  gem 'spring',                '2.0.2'
  gem 'spring-watcher-listen', '2.0.1'
end

group :production do
  gem 'pg', '0.20.0'
end

Gem
1source 'https://rubygems.org'
2
3gem 'rails',        '5.1.6'
4gem 'puma',         '3.9.1'
5gem 'sass-rails',   '5.0.6'
6gem 'uglifier',     '3.2.0'
7gem 'coffee-rails', '4.2.2'
8gem 'jquery-rails', '4.3.1'
9gem 'turbolinks',   '5.0.1'
10gem 'jbuilder',     '2.7.0'
11
12group :development, :test do
13  gem 'sqlite3', '1.3.13'
14  gem 'byebug',  '9.0.6', platform: :mri
15end
16
17group :development do
18  gem 'web-console',           '3.5.1'
19  gem 'listen',                '3.1.5'
20  gem 'spring',                '2.0.2'
21  gem 'spring-watcher-listen', '2.0.1'
22end
23
24group :production do
25  gem 'pg', '0.20.0'
26end

GEMFile.lock

  remote: https://rubygems.org/
  specs:
    actioncable (5.1.2)
      actionpack (= 5.1.2)
      nio4r (~> 2.0)
      websocket-driver (~> 0.6.1)
    actionmailer (5.1.2)
      actionpack (= 5.1.2)
      actionview (= 5.1.2)
      activejob (= 5.1.2)
      mail (~> 2.5, >= 2.5.4)
      rails-dom-testing (~> 2.0)
    actionpack (5.1.2)
      actionview (= 5.1.2)
      activesupport (= 5.1.2)
      rack (~> 2.0)
      rack-test (~> 0.6.3)
      rails-dom-testing (~> 2.0)
      rails-html-sanitizer (~> 1.0, >= 1.0.2)
    actionview (5.1.2)
      activesupport (= 5.1.2)
      builder (~> 3.1)
      erubi (~> 1.4)
      rails-dom-testing (~> 2.0)
      rails-html-sanitizer (~> 1.0, >= 1.0.3)
    activejob (5.1.2)
      activesupport (= 5.1.2)
      globalid (>= 0.3.6)
    activemodel (5.1.2)
      activesupport (= 5.1.2)
    activerecord (5.1.2)
      activemodel (= 5.1.2)
      activesupport (= 5.1.2)
      arel (~> 8.0)
    activesupport (5.1.2)
      concurrent-ruby (~> 1.0, >= 1.0.2)
      i18n (~> 0.7)
      minitest (~> 5.1)
      tzinfo (~> 1.1)
    arel (8.0.0)
    bindex (0.8.1)
    builder (3.2.4)
    byebug (9.0.6)
    coffee-rails (4.2.2)
      coffee-script (>= 2.2.0)
      railties (>= 4.0.0)
    coffee-script (2.4.1)
      coffee-script-source
      execjs
    coffee-script-source (1.12.2)
    concurrent-ruby (1.1.5)
    crass (1.0.6)
    erubi (1.9.0)
    execjs (2.7.0)
    ffi (1.12.1)
    globalid (0.4.2)
      activesupport (>= 4.2.0)
    i18n (0.9.5)
      concurrent-ruby (~> 1.0)
    jbuilder (2.6.4)
      activesupport (>= 3.0.0)
      multi_json (>= 1.2)
    jquery-rails (4.3.1)
      rails-dom-testing (>= 1, < 3)
      railties (>= 4.2.0)
      thor (>= 0.14, < 2.0)
    listen (3.1.5)
      rb-fsevent (~> 0.9, >= 0.9.4)
      rb-inotify (~> 0.9, >= 0.9.7)
      ruby_dep (~> 1.2)
    loofah (2.4.0)
      crass (~> 1.0.2)
      nokogiri (>= 1.5.9)
    mail (2.7.1)
      mini_mime (>= 0.1.1)
    method_source (0.9.2)
    mini_mime (1.0.2)
    mini_portile2 (2.4.0)
    minitest (5.14.0)
    multi_json (1.14.1)
    nio4r (2.5.2)
    nokogiri (1.10.7)
      mini_portile2 (~> 2.4.0)
    puma (3.9.1)
    rack (2.1.1)
    rack-test (0.6.3)
      rack (>= 1.0)
    rails (5.1.2)
      actioncable (= 5.1.2)
      actionmailer (= 5.1.2)
      actionpack (= 5.1.2)
      actionview (= 5.1.2)
      activejob (= 5.1.2)
      activemodel (= 5.1.2)
      activerecord (= 5.1.2)
      activesupport (= 5.1.2)
      bundler (>= 1.3.0, < 2.0)
      railties (= 5.1.2)
      sprockets-rails (>= 2.0.0)
    rails-dom-testing (2.0.3)
      activesupport (>= 4.2.0)
      nokogiri (>= 1.6)
    rails-html-sanitizer (1.3.0)
      loofah (~> 2.3)
    railties (5.1.2)
      actionpack (= 5.1.2)
      activesupport (= 5.1.2)
      method_source
      rake (>= 0.8.7)
      thor (>= 0.18.1, < 2.0)
    rake (13.0.1)
    rb-fsevent (0.10.3)
    rb-inotify (0.10.1)
      ffi (~> 1.0)
    ruby_dep (1.5.0)
    sass (3.7.4)
      sass-listen (~> 4.0.0)
    sass-listen (4.0.0)
      rb-fsevent (~> 0.9, >= 0.9.4)
      rb-inotify (~> 0.9, >= 0.9.7)
    sass-rails (5.0.6)
      railties (>= 4.0.0, < 6)
      sass (~> 3.1)
      sprockets (>= 2.8, < 4.0)
      sprockets-rails (>= 2.0, < 4.0)
      tilt (>= 1.1, < 3)
    spring (2.0.2)
      activesupport (>= 4.2)
    spring-watcher-listen (2.0.1)
      listen (>= 2.7, < 4.0)
      spring (>= 1.2, < 3.0)
    sprockets (3.7.2)
      concurrent-ruby (~> 1.0)
      rack (> 1, < 3)
    sprockets-rails (3.2.1)
      actionpack (>= 4.0)
      activesupport (>= 4.0)
      sprockets (>= 3.0.0)
    sqlite3 (1.3.13)
    thor (1.0.1)
    thread_safe (0.3.6)
    tilt (2.0.10)
    turbolinks (5.0.1)
      turbolinks-source (~> 5)
    turbolinks-source (5.2.0)
    tzinfo (1.2.6)
      thread_safe (~> 0.1)
    uglifier (3.2.0)
      execjs (>= 0.3.0, < 3)
    web-console (3.5.1)
      actionview (>= 5.0)
      activemodel (>= 5.0)
      bindex (>= 0.4.0)
      railties (>= 5.0)
    websocket-driver (0.6.5)
      websocket-extensions (>= 0.1.0)
    websocket-extensions (0.1.4)

PLATFORMS
  ruby

DEPENDENCIES
  byebug (= 9.0.6)
  coffee-rails (= 4.2.2)
  jbuilder (= 2.6.4)
  jquery-rails (= 4.3.1)
  listen (= 3.1.5)
  puma (= 3.9.1)
  rails (= 5.1.2)
  sass-rails (= 5.0.6)
  spring (= 2.0.2)
  spring-watcher-listen (= 2.0.1)
  sqlite3 (= 1.3.13)
  turbolinks (= 5.0.1)
  uglifier (= 3.2.0)
  web-console (= 3.5.1)

BUNDLED WITH
   1.17.3