Nuget repository ignores dependencies of packages
~"backend-weight::3"
### Summary
Dependencies of packages pushed to the NuGet Repository are not shown in e. g. Visual Studio when browsing the dependency. The dependencies are not resolved either when installing the package.
### Steps to reproduce
1. Push any package with dependencies to a GitLab NuGet Repo.
1. Get any package with dependencies from nuget.org, e.g. https://www.nuget.org/packages/Moq/
1. Add the project as a package source in Visual Studio (Tools/Options/Nuget package manager/package soruces).
1. This is with Visual Studio 2017 V15.9.12, .net framework 4.5 and the project converted to PackageReference (https://docs.microsoft.com/en-us/nuget/consume-packages/migrate-packages-config-to-package-reference)
1. Browse the new source, see then dependencies missing
1. If you push to a simple file store `nuget push f:\tmp\moq.4.13.1.nupkg -source "mysource"` the dependencies show up
### Further details
- The .nuspec file inside contains:
```
<dependencies>
<group targetFramework=".NETFramework4.5">
<dependency id="Castle.Core" version="4.4.0" exclude="Build,Analyzers" />
<dependency id="System.Threading.Tasks.Extensions" version="4.5.1" exclude="Build,Analyzers" />
</group>
<group targetFramework=".NETStandard2.0">
<dependency id="Castle.Core" version="4.4.0" exclude="Build,Analyzers" />
<dependency id="System.Threading.Tasks.Extensions" version="4.5.1" exclude="Build,Analyzers" />
</group>
</dependencies>
```
- 
- 
### What is the current *bug* behavior?
Dependencies of package are not displayed and not installed
### What is the expected *correct* behavior?
Dependencies of package are displayed and installed
Gitlab 12.8.7-ee
issue