Cleanup for .NET Standard 2.1

Author: Oren (electricessence)

Open.Text.CSV.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
     <AssemblyName>Open.Text.CSV</AssemblyName>
     <RootNamespace>Open.Text.CSV</RootNamespace>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
@@ -11,15 +11,16 @@
 
 Part of the "Open" set of libraries.</Description>
     <Copyright>https://github.com/electricessence/Open.Text.CSV/blob/master/LISCENSE.md</Copyright>
-    <PackageLicenseUrl>https://github.com/electricessence/Open.Text.CSV/blob/master/LISCENSE.md</PackageLicenseUrl>
+    <PackageLicenseUrl></PackageLicenseUrl>
     <PackageProjectUrl>https://github.com/electricessence/Open.Text.CSV/</PackageProjectUrl>
     <RepositoryUrl>https://github.com/electricessence/Open.Text.CSV/</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>csv, csharp, dotnetcore, textwriter, streamreader</PackageTags>
-    <Version>2.0.0</Version>
-    <AssemblyVersion>2.0.0.0</AssemblyVersion>
-    <FileVersion>2.0.0.0</FileVersion>
+    <Version>2.0.1</Version>
+    <AssemblyVersion>2.0.1.0</AssemblyVersion>
+    <FileVersion>2.0.1.0</FileVersion>
     <PackageReleaseNotes></PackageReleaseNotes>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
@@ -43,8 +44,11 @@ Part of the "Open" set of libraries.</Description>
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Open.Disposable" Version="1.2.1" />
-    <PackageReference Include="Open.Text" Version="2.0.4" />
+    <PackageReference Include="Open.Disposable" Version="2.0.1" />
+    <PackageReference Include="Open.Text" Version="2.0.5" />
+  </ItemGroup>
+  
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
     <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.2" />
   </ItemGroup>