Update dependencies from https://github.com/dotnet/arcade build 20190226.6 (#267)

This change updates the following dependencies
- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19126.6

eng/Version.Details.xml

@@ -44,9 +44,9 @@
       <Uri>https://github.com/aspnet/Extensions</Uri>
       <Sha>150939790e7ed873ed0a90cd55418091bccb0b1f</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19125.2">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19126.6">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>a0ed7c38c714b1f60f50a4a408171e2c3bcf8f7f</Sha>
+      <Sha>3f38c38af31863b35c9334320b95cca56e29c942</Sha>
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>

global.json

@@ -12,6 +12,6 @@
     "version": "3.0.100-preview3-010280"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "1.0.0-beta.19125.2"
+    "Microsoft.DotNet.Arcade.Sdk": "1.0.0-beta.19126.6"
   }
 }