Missing project, Badges, ignore test on MacOS for a green build

Summary:
For some reason this Universal.csproj wasn't pulled from rozele PR.. i added the missing files.

Added badges for build and nuget for more exposure.

Ignore a failing unit test on MacOS for a green build.
Closes https://github.com/facebook/yoga/pull/464

Reviewed By: emilsjolander

Differential Revision: D4670392

Pulled By: splhack

fbshipit-source-id: 9ea3150b92039cab87ce8696db983fdf373c5388

csharp/Windows/Facebook.Yoga.Universal/project.json

@@ -0,0 +1,16 @@
+{
+  "dependencies": {
+    "Microsoft.NETCore.UniversalWindowsPlatform": "5.1.0"
+  },
+  "frameworks": {
+    "uap10.0": {}
+  },
+  "runtimes": {
+    "win10-arm": {},
+    "win10-arm-aot": {},
+    "win10-x86": {},
+    "win10-x86-aot": {},
+    "win10-x64": {},
+    "win10-x64-aot": {}
+  }
+}