Unlinking exe file fails on installation

I just noticed that the service uninstallation has trouble unlinking the exe file on my machine. This may be user error, in which case I apologize.

```
fs.js:760
return binding.unlink(pathModule._makeLong(path));
^
Error: EPERM, operation not permitted 'C:\Users\pschuegr\Documents\GitHub\wt\package\daemon\wt.exe'
at Object.fs.unlinkSync (fs.js:760:18)
at rm (C:\Users\pschuegr\AppData\Roaming\npm\node_modules\node-windows\lib\daemon.js:458:22)
at C:\Users\pschuegr\AppData\Roaming\npm\node_modules\node-windows\lib\daemon.js:471:15
at ChildProcess.exithandler (child_process.js:635:7)
at ChildProcess.EventEmitter.emit (events.js:98:17)
at maybeClose (child_process.js:735:16)
at Socket. (child_process.js:948:11)
at Socket.EventEmitter.emit (events.js:95:17)
at Pipe.close (net.js:466:12)
npm ERR! weird error 8
npm ERR! not ok code 0
```