title: Command npm run build error
body: <p>I've downloaded the swagger-js zip from <a href="https://github.com/swagger-api/swagger-js" rel="nofollow noreferrer">https://github.com/swagger-api/swagger-js</a>, and I have modified some file, so I need to rebuild it. The command npm install works correctly, but when I run the command npm run build it fail and return me some errors, this is the content of the npm-debug.log:</p>
  
  <pre><code>0 info it worked if it ends with ok  
  1 verbose cli [ 'C:\\Program Files\\nodejs\\node.exe',  
  1 verbose cli   'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',  
  1 verbose cli   'run',  
  1 verbose cli   'build' ]  
  2 info using npm@3.10.10  
  3 info using node@v6.10.3  
  4 verbose run-script [ 'prebuild', 'build', 'postbuild' ]  
  5 info lifecycle swagger-client@3.0.11~prebuild: swagger-client@3.0.11  
  6 silly lifecycle swagger-client@3.0.11~prebuild: no script for prebuild, continuing  
  7 info lifecycle swagger-client@3.0.11~build: swagger-client@3.0.11  
  8 verbose lifecycle swagger-client@3.0.11~build: unsafe-perm in lifecycle true  
  9 verbose lifecycle swagger-client@3.0.11~build: PATH: C:\Program Files\nodejs\node_modules\npm\bin\node-gyp-bin;C:\Users\Sibo\Desktop\swagger-ui\swagger-js-master\swagger-js-master\node_modules\.bin;C:\Python27;C:\PCI Geomatics\Geomatica 2017\exe;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files\MATLAB\R2016b\bin;C:\Program Files (x86)\Brackets\command;C:\Program Files\nodejs\;C:\Users\Sibo\AppData\Local\Microsoft\WindowsApps;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Users\Sibo\AppData\Roaming\npm  
  10 verbose lifecycle swagger-client@3.0.11~build: CWD: C:\Users\Sibo\Desktop\swagger-ui\swagger-js-master\swagger-js-master  
  11 silly lifecycle swagger-client@3.0.11~build: Args: [ '/d /s /c',
  11 silly lifecycle   'NODE_ENV=production webpack -p --config ./webpack.config.js' ]  
  12 silly lifecycle swagger-client@3.0.11~build: Returned: code: 1  signal: null  
  13 info lifecycle swagger-client@3.0.11~build: Failed to exec build script  
  14 verbose stack Error: swagger-client@3.0.11 build: `NODE_ENV=production webpack -p --config ./webpack.config.js`  
  14 verbose stack Exit status 1  
  14 verbose stack     at EventEmitter.&lt;anonymous&gt; (C:\Program Files\nodejs\node_modules\npm\lib\utils\lifecycle.js:255:16)  
  14 verbose stack     at emitTwo (events.js:106:13)  
  14 verbose stack     at EventEmitter.emit (events.js:191:7)  
  14 verbose stack     at ChildProcess.&lt;anonymous&gt; (C:\Program Files\nodejs\node_modules\npm\lib\utils\spawn.js:40:14)  
  14 verbose stack     at emitTwo (events.js:106:13)  
  14 verbose stack     at ChildProcess.emit (events.js:191:7)  
  14 verbose stack     at maybeClose (internal/child_process.js:886:16)  
  14 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:226:5)  
  15 verbose pkgid swagger-client@3.0.11  
  16 verbose cwd C:\Users\Sibo\Desktop\swagger-ui\swagger-js-master\swagger-js-master  
  17 error Windows_NT 10.0.14393  
  18 error argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "run" "build"  
  19 error node v6.10.3  
  20 error npm  v3.10.10  
  21 error code ELIFECYCLE  
  22 error swagger-client@3.0.11 build: `NODE_ENV=production webpack -p --config ./webpack.config.js`  
  22 error Exit status 1  
  23 error Failed at the swagger-client@3.0.11 build script 'NODE_ENV=production webpack -p --config ./webpack.config.js'.  
  23 error Make sure you have the latest version of node.js and npm installed.  
  23 error If you do, this is most likely a problem with the swagger-client package,  
  23 error not with npm itself.  
  23 error Tell the author that this fails on your system:  
  23 error     NODE_ENV=production webpack -p --config ./webpack.config.js 
  23 error You can get information on how to open an issue for this project with:  
  23 error     npm bugs swagger-client  
  23 error Or if that isn't available, you can get their info via:  
  23 error     npm owner ls swagger-client  
  23 error There is likely additional logging output above.  
  24 verbose exit [ 1, true ]  
  </code></pre>
  
  <p>I'm using windows 10<br>
  nodejs version: 6.10.3<br>
  npm versione: 3.10.10  </p>