Wrong project URL in .nuspec

The file `YNAB.Rest.nuspec` has an incorrect project url.  Project name should be YNAB-Rest, not YNAB.Rest.  The current value is
```
<projectUrl>https://gitlab.com/jsmarble/YNAB.Rest</projectUrl>
```
But the value should be
```
<projectUrl>https://gitlab.com/jsmarble/YNAB-Rest</projectUrl>
```