Could not resolve this reference. Could not locate the assembly "PresentationCore"

The build failed here https://travis-ci.org/github/ChuckHearthstone/CardQuery/builds/734951387
Could not resolve this reference. Could not locate the assembly “PresentationFramework”. Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors. [/home/travis/build/ChuckHearthstone/CardQuery/CardQuery/CardQuery.csproj]

The project on my local computer can be compiled, and the file is located at C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.7.2\PresentationCore.dll.
And the location find in above build is
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationCore.winmd”, but it didn’t exist.
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationCore.dll”, but it didn’t exist.
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationCore.exe”, but it didn’t exist.
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationFramework.winmd”, but it didn’t exist.
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationFramework.dll”, but it didn’t exist.
Considered “/usr/lib/mono/xbuild-frameworks/.NETFramework/v4.7.2/PresentationFramework.exe”, but it didn’t exist.

Find an explanation here

Basically, WPF isn’t supported by Mono (or .NET running on any platform other than Windows).

You’ll need to find a Windows-based CI service such as AppVeyor instead.