title: error running 'npm run dist' to build bootstrap4
body: <p>I downloaded and extracted Bootstrap 4 today and am getting an error:</p>
  
  <p><strong>Setup</strong></p>
  
  <pre><code>pwd
  /Volumes/projects/bs4_temp/bootstrap-4.0.0
  kevin $ dir
  total 1432
  drwxr-xr-x  14 kevin  staff   16384 28 May 15:36 .
  drwxr-xr-x   8 kevin  staff   16384 29 May 15:15 ..
  -rwxr-xr-x   1 kevin  staff     313 18 Jan 09:29 .babelrc.js
  -rwxr-xr-x   1 kevin  staff     208 18 Jan 09:29 .editorconfig
  -rwxr-xr-x   1 kevin  staff      56 18 Jan 09:29 .eslintignore
  -rwxr-xr-x   1 kevin  staff    7123 18 Jan 09:29 .eslintrc.json
  -rwxr-xr-x   1 kevin  staff     359 18 Jan 09:29 .gitattributes
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 .github
  -rwxr-xr-x   1 kevin  staff     517 18 Jan 09:29 .gitignore
  -rwxr-xr-x   1 kevin  staff      45 18 Jan 09:29 .stylelintignore
  -rwxr-xr-x   1 kevin  staff    6685 18 Jan 09:29 .stylelintrc
  -rwxr-xr-x   1 kevin  staff     782 18 Jan 09:29 .travis.yml
  -rwxr-xr-x   1 kevin  staff      17 18 Jan 09:29 CNAME
  -rwxr-xr-x   1 kevin  staff    3217 18 Jan 09:29 CODE_OF_CONDUCT.md
  -rwxr-xr-x   1 kevin  staff     199 18 Jan 09:29 Gemfile
  -rwxr-xr-x   1 kevin  staff    1905 18 Jan 09:29 Gemfile.lock
  -rwxr-xr-x   1 kevin  staff    1131 18 Jan 09:29 LICENSE
  -rwxr-xr-x   1 kevin  staff    9138 18 Jan 09:29 README.md
  -rwxr-xr-x   1 kevin  staff    2505 18 Jan 09:29 _config.yml
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 _data
  drwxr-xr-x   3 kevin  staff   16384 18 Jan 09:29 _includes
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 _layouts
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 _plugins
  drwxr-xr-x   7 kevin  staff   16384 18 Jan 09:29 assets
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 build
  -rwxr-xr-x   1 kevin  staff     744 18 Jan 09:29 composer.json
  drwxr-xr-x   4 kevin  staff   16384 18 Jan 09:29 dist
  drwxr-xr-x   3 kevin  staff   16384 18 Jan 09:29 docs
  -rwxr-xr-x   1 kevin  staff    5430 18 Jan 09:29 favicon.ico
  -rwxr-xr-x   1 kevin  staff    4384 18 Jan 09:29 index.html
  drwxr-xr-x   5 kevin  staff   16384 18 Jan 09:29 js
  drwxr-xr-x   2 kevin  staff   16384 18 Jan 09:29 nuget
  -rwxr-xr-x   1 kevin  staff  433474 18 Jan 09:29 package-lock.json
  -rwxr-xr-x   1 kevin  staff     530 18 Jan 09:29 package.js
  -rwxr-xr-x   1 kevin  staff    9152 18 Jan 09:29 package.json
  -rwxr-xr-x   1 kevin  staff     123 18 Jan 09:29 robots.txt
  -rwxr-xr-x   1 kevin  staff     249 18 Jan 09:29 sache.json
  drwxr-xr-x   4 kevin  staff   16384 18 Jan 09:29 scss
  -rwxr-xr-x   1 kevin  staff     114 18 Jan 09:29 sw.js
  
  kevin $ npm --version
  6.1.0
  </code></pre>
  
  <p><strong>The error</strong></p>
  
  <pre><code>kevin $ npm run dist
  
  &gt; bootstrap@4.0.0 dist /Volumes/projects/bs4_temp/bootstrap-4.0.0
  &gt; npm-run-all --parallel css js
  
  sh: npm-run-all: command not found
  npm ERR! file sh
  npm ERR! code ELIFECYCLE
  npm ERR! errno ENOENT
  npm ERR! syscall spawn
  npm ERR! bootstrap@4.0.0 dist: `npm-run-all --parallel css js`
  npm ERR! spawn ENOENT
  npm ERR! 
  npm ERR! Failed at the bootstrap@4.0.0 dist script.
  npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
  npm WARN Local package.json exists, but node_modules missing, did you mean to install?
  
  npm ERR! A complete log of this run can be found in:
  npm ERR!     /Users/kevin/.npm/_logs/2018-05-29T16_20_07_838Z-debug.log
  </code></pre>
  
  <p><strong>Observations</strong></p>
  
  <p><em>[Ignore this:  I believe the current version is 4.1 yet despite looking and trying several times, I seem to be downloading 4.0.0 each time I try. ]</em></p>
  
  <p>Edit - downloaded 4.1.1 from another computer. This gives same error and also does not have the node_modules dir.</p>
  
  <p>I last looked at this on Feb (at v4.0.0)and running the same NPM command in that older directory works. Comparing the two directories, the one I used in Feb has a <em>node_modules</em> sub dir and the current ZIP does not (nor does the git appear to have one).</p>
  
  <p>Is this my problem, and if so why is <em>node_modules</em> missing from the ZIP file today?</p>