use ext for now

Rx.NET/Source/Directory.build.props

@@ -17,6 +17,7 @@
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <DefaultLanguage>en-US</DefaultLanguage>
     <WriteVersionInfoToBuildLog>false</WriteVersionInfoToBuildLog>
+    <IncludeSymbols>true</IncludeSymbols>
   </PropertyGroup>
   
     <ItemGroup>

Rx.NET/Source/Directory.build.targets

@@ -1,7 +1,7 @@
 <Project>  
   <!-- This has to be set in targets as the default props will overwrite -->
   <PropertyGroup>
-    <DebugType>embedded</DebugType>
+    <DebugType>portable</DebugType>
   </PropertyGroup>
   
   <!-- This props all need to be set in targets as they depend on the values set earlier -->

Rx.NET/Source/tests/Tests.System.Reactive/Tests.System.Reactive.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp1.0;net46</TargetFrameworks>
+    <TargetFrameworks>net46;netcoreapp1.0</TargetFrameworks>
     <NoWarn>$(NoWarn);CS0618</NoWarn>
   </PropertyGroup>