title: Upgrading to Rails 5, can't resolve dependencies
body: <p>Upgrading from Rails 4.2.10 to Rails 5.1.4 results in the error message below. I am not sure how t resolve the dependencies. The ruby version is 2.5.1. Rails 4.2.10 runs without issue and <code>bundle upgrade</code> runs without returning any errors.</p>
  
  <p><strong>Update:</strong> added Gemfile below for reference. When deleting <code>Gemfile.lock</code> prior to performing <code>bundle update</code>, the below error message is still generated. </p>
  
  <p><strong>Error Message</strong></p>
  
  <pre><code>Bundler could not find compatible versions for gem "activemodel":
    In Gemfile:
      rails (~&gt; 5.1.4) was resolved to 5.1.4, which depends on
        activemodel (= 5.1.4)
  
  web-console (~&gt; 2.0.0.beta3) was resolved to 2.0.0, which depends on
    activemodel (~&gt; 4.0)
  
  Bundler could not find compatible versions for gem "activesupport":
    In Gemfile:
      jbuilder (~&gt; 2.7.0) was resolved to 2.7.0, which depends on
    activesupport (&gt;= 4.2.0)
  
  rails (~&gt; 5.1.4) was resolved to 5.1.4, which depends on
    activesupport (= 5.1.4)
  
  Bundler could not find compatible versions for gem "rails":
    In Gemfile:
      rails (~&gt; 5.1.4)
  
  Could not find gem 'rails (~&gt; 5.1.4)' in any of the sources.Bundler could not 
  find compatible versions for gem "activemodel":
    In Gemfile:
      rails (~&gt; 5.1.4) was resolved to 5.1.4, which depends on
        activemodel (= 5.1.4)
  
  web-console (~&gt; 2.0.0.beta3) was resolved to 2.0.0, which depends on
    activemodel (~&gt; 4.0)
  
  Bundler could not find compatible versions for gem "activesupport":
    In Gemfile:
  jbuilder (~&gt; 2.7.0) was resolved to 2.7.0, which depends on
    activesupport (&gt;= 4.2.0)
  
  rails (~&gt; 5.1.4) was resolved to 5.1.4, which depends on
    activesupport (= 5.1.4)
  
  Bundler could not find compatible versions for gem "rails":
    In Gemfile:
  rails (~&gt; 5.1.4)
  
  Could not find gem 'rails (~&gt; 5.1.4)' in any of the sources.
  </code></pre>
  
  <p><strong>Gemfile</strong></p>
  
  <pre><code>source 'https://rubygems.org'
  
  gem 'rails', '~&gt; 5.1.4'
  gem 'sass-rails'
  gem 'bootstrap-sass'
  gem 'bcrypt'
  gem 'uglifier',     '~&gt; 3.2.0'
  gem 'coffee-rails', '~&gt; 4.2.2'
  gem 'jquery-rails', '~&gt; 4.3.1'
  gem 'turbolinks',   '~&gt; 5.0.1'
  gem 'jbuilder',     '~&gt; 2.7.0'
  gem 'sdoc', '~&gt; 0.4.0', group: :doc
  gem 'stripe'
  
  group :development, :test do
    gem 'sqlite3',     '~&gt; 1.3.9'
    gem 'byebug',      '~&gt; 3.4.0'
    gem 'web-console', '~&gt; 2.0.0.beta3'
    gem 'spring',      '~&gt; 1.1.3'
  end
  
  group :test do
    gem 'minitest-reporters', '~&gt; 1.0.5'
    gem 'mini_backtrace',     '~&gt; 0.1.3'
    gem 'guard-minitest',     '~&gt; 2.3.1'
  end
  
  group :production do
    gem 'pg',             '0.17.1'
    gem 'rails_12factor', '0.0.2'
    gem 'puma'
  end
  </code></pre>