title: Bcrypt 3.0.1 fails to install on node v 8.12.0
body: <p>Bcrypt 3.0.1 fails to install on node v 8.12.0</p>
  
  <p>npm debug log:</p>
  
  <pre><code>1224 verbose stack Error: bcrypt@3.0.0 install: `node-pre-gyp install --fallback-to-build`
  1224 verbose stack Exit status 1
  1224 verbose stack     at EventEmitter.&lt;anonymous&gt; (d:\brd\app\node-v8.12.0-win-x64\node_modules\npm\node_modules\npm-lifecycle\index.js:301:16)
  1224 verbose stack     at emitTwo (events.js:126:13)
  1224 verbose stack     at EventEmitter.emit (events.js:214:7)
  1224 verbose stack     at ChildProcess.&lt;anonymous&gt; (d:\brd\app\node-v8.12.0-win-x64\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
  1224 verbose stack     at emitTwo (events.js:126:13)
  1224 verbose stack     at ChildProcess.emit (events.js:214:7)
  1224 verbose stack     at maybeClose (internal/child_process.js:915:16)
  1224 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)
  1225 verbose pkgid bcrypt@3.0.0
  1226 verbose cwd d:\brd\proj\2018\projects\projectname
  1227 verbose Windows_NT 6.1.7601
  1228 verbose argv "d:\\brd\\app\\node-v8.12.0-win-x64\\node.exe" "d:\\brd\\app\\node-v8.12.0-win-x64\\node_modules\\npm\\bin\\npm-cli.js" "i" "bcrypt@3.0.0" "--save"
  1229 verbose node v8.12.0
  1230 verbose npm  v6.4.1
  1231 error code ELIFECYCLE
  1232 error errno 1
  1233 error bcrypt@3.0.0 install: `node-pre-gyp install --fallback-to-build`
  1233 error Exit status 1
  1234 error Failed at the bcrypt@3.0.0 install script.
  1234 error This is probably not a problem with npm. There is likely additional logging output above.
  </code></pre>
  
  <p>as stated <a href="https://github.com/kelektiv/node.bcrypt.js/issues/650" rel="nofollow noreferrer">here</a> it seems that this issue has  been fix by this PR (<a href="https://github.com/kelektiv/node.bcrypt.js/pull/649" rel="nofollow noreferrer">#649</a>) but the fix hasn't been released on the npm repo yet.</p>
  
  <p>any idea how to fix this ?</p>