title: Bundler could not find compatible versions for gem "railties" when bundle update
body: <p>I searched the SO, there are several related question, but can not solve my issue.</p>
  
  <p>When I run: <code>$ bundle update</code></p>
  
  <blockquote>
    <p>Fetching gem metadata from <a href="https://gems.ruby-china.org/" rel="nofollow noreferrer">https://gems.ruby-china.org/</a>..........<br>
        Fetching version metadata from <a href="https://gems.ruby-china.org/" rel="nofollow noreferrer">https://gems.ruby-china.org/</a>..<br>
        Resolving dependencies...<br>
        Bundler could not find compatible versions for gem "railties":<br>
          In Gemfile:<br>
            devise (~> 3.5.0) was resolved to 3.5.1, which depends on<br>
              railties (&lt; 5, >= 3.2.6)<br>
            rails (~> 5.0.1) was resolved to 5.0.1, which depends on<br>
              railties (= 5.0.1)  </p>
  </blockquote>
  
  <p>The picture is below:</p>
  
  <p><a href="https://i.stack.imgur.com/P3iEJ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/P3iEJ.jpg" alt="enter image description here"></a></p>
  
  <p>And, I run <code>$ rails -v</code>:</p>
  
  <blockquote>
    <p>Could not find gem 'devise (~> 3.5.0)' in any of the gem sources listed in your Gemfile or available on this machine.</p>
  </blockquote>