Update Benchmark runtime to .NET 4.7.

Author: bgrainger

tests/Benchmark/Benchmark.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>netcoreapp1.1;net462;netcoreapp2.0</TargetFrameworks>
+    <TargetFrameworks>netcoreapp1.1;net47;netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.10.8" />

tests/Benchmark/Program.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Data.Common;
 using System.Threading.Tasks;
 using BenchmarkDotNet.Attributes;
@@ -24,7 +24,7 @@ static void Main()
 				.With(JitOptimizationsValidator.FailOnError)
 				.With(MemoryDiagnoser.Default)
 				.With(StatisticColumn.AllStatistics)
-				.With(Job.Default.With(Runtime.Clr).With(Jit.RyuJit).With(Platform.X64).With(CsProjClassicNetToolchain.Net462).WithId("net462"))
+				.With(Job.Default.With(Runtime.Clr).With(Jit.RyuJit).With(Platform.X64).With(CsProjClassicNetToolchain.Net47).WithId("net47"))
 				.With(Job.Default.With(Runtime.Core).With(CsProjCoreToolchain.NetCoreApp11).WithId("netcore11"))
 				.With(Job.Default.With(Runtime.Core).With(CsProjCoreToolchain.NetCoreApp20).WithId("netcore20"))
 				.With(DefaultExporters.Csv);