Version number ignored in Addins\packages.config

Start with this packages.config file:

```

```
run build.ps1 and it'll download the package.

Update packages.config with the new version:

```

```
and run build.ps1.

The Addins folder incorrectly contains version 130.3485.1.

This scenario plays out when you commit the packages.config folder to source control, but not the packages themselves. When one developer updates packages.config, all the other developers continue to use the old version of the package.