Error parsing EntityName from nuspec file

Hey,

I'm getting the following error when trying to build an installer...

```
[START] Electron Winstaller
electron-windows-installer:main Using Mono: 'mono' +0ms
electron-windows-installer:main Using Wine: 'wine' +3ms
electron-windows-installer:main Created NuSpec file:

wmail
wmail
1.2.4
Thomas Beverley
Thomas Beverley
https://raw.githubusercontent.com/atom/electron/master/atom/browser/resources/win/atom.ico
false
The missing desktop client for Gmail & Google Inbox
Copyright © 2016 Thomas Beverley

+7s
[Error: Failed with exit code: 1
Output:
Attempting to build package from 'wmail.nuspec'.
An error occurred while parsing EntityName. Line 1, position 39.
]
```

Has anyone else seen this? I'm using el-capitan with mono 4.2.3