Add dotnet gitignore, clean up unneeded files

.gitignore

+*.swp
+*.*~
+project.lock.json
+.DS_Store
+*.pyc
+nupkg/
+
+# Visual Studio Code
+.vscode
+
+# User-specific files
+*.suo
+*.user
+*.userosscache
+*.sln.docstates
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+build/
+bld/
+[Bb]in/
+[Oo]bj/
+[Oo]ut/
+msbuild.log
+msbuild.err
+msbuild.wrn

obj/dotnetcore.csproj.nuget.cache

-{
-  "version": 1,
-  "dgSpecHash": "OrVZdV0fD9rX0Gv4lp3hfPmpH7ejQzvoekKk+OeTUrYxwtJNeYVye1qM5uKmrlBrfAg/zA1FJayL/QWK0609tw==",
-  "success": true
-}
\ No newline at end of file

obj/dotnetcore.csproj.nuget.g.props

-<?xml version="1.0" encoding="utf-8" standalone="no"?>
-<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup Condition=" '$(ExcludeRestorePackageImports)' != 'true' ">
-    <RestoreSuccess Condition=" '$(RestoreSuccess)' == '' ">True</RestoreSuccess>
-    <RestoreTool Condition=" '$(RestoreTool)' == '' ">NuGet</RestoreTool>
-    <ProjectAssetsFile Condition=" '$(ProjectAssetsFile)' == '' ">/mnt/c/code/dotnetcore/obj/project.assets.json</ProjectAssetsFile>
-    <NuGetPackageRoot Condition=" '$(NuGetPackageRoot)' == '' ">/root/.nuget/packages/</NuGetPackageRoot>
-    <NuGetPackageFolders Condition=" '$(NuGetPackageFolders)' == '' ">/root/.nuget/packages/;/usr/share/dotnet/sdk/NuGetFallbackFolder</NuGetPackageFolders>
-    <NuGetProjectStyle Condition=" '$(NuGetProjectStyle)' == '' ">PackageReference</NuGetProjectStyle>
-    <NuGetToolVersion Condition=" '$(NuGetToolVersion)' == '' ">4.9.3</NuGetToolVersion>
-  </PropertyGroup>
-  <PropertyGroup>
-    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
-  </PropertyGroup>
-  <ImportGroup Condition=" '$(ExcludeRestorePackageImports)' != 'true' ">
-    <Import Project="/usr/share/dotnet/sdk/NuGetFallbackFolder/microsoft.netcore.app/2.2.0/build/netcoreapp2.2/Microsoft.NETCore.App.props" Condition="Exists('/usr/share/dotnet/sdk/NuGetFallbackFolder/microsoft.netcore.app/2.2.0/build/netcoreapp2.2/Microsoft.NETCore.App.props')" />
-  </ImportGroup>
-</Project>
\ No newline at end of file

obj/dotnetcore.csproj.nuget.g.targets

-<?xml version="1.0" encoding="utf-8" standalone="no"?>
-<Project ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
-  </PropertyGroup>
-  <ImportGroup Condition=" '$(ExcludeRestorePackageImports)' != 'true' ">
-    <Import Project="/usr/share/dotnet/sdk/NuGetFallbackFolder/netstandard.library/2.0.3/build/netstandard2.0/NETStandard.Library.targets" Condition="Exists('/usr/share/dotnet/sdk/NuGetFallbackFolder/netstandard.library/2.0.3/build/netstandard2.0/NETStandard.Library.targets')" />
-    <Import Project="/usr/share/dotnet/sdk/NuGetFallbackFolder/microsoft.netcore.app/2.2.0/build/netcoreapp2.2/Microsoft.NETCore.App.targets" Condition="Exists('/usr/share/dotnet/sdk/NuGetFallbackFolder/microsoft.netcore.app/2.2.0/build/netcoreapp2.2/Microsoft.NETCore.App.targets')" />
-  </ImportGroup>
-</Project>
\ No newline at end of file