Install RC3 and preview4 CLI while we transition repos

This should only take a few days....hopefully.

build/KoreBuild.ps1

@@ -52,6 +52,8 @@ if ($env:KOREBUILD_SKIP_RUNTIME_INSTALL -eq "1")
 else
 {
     # Install the version of dotnet-cli used to compile
+    # TODO temporarily install preview4 while we move to RC3
+    & "$koreBuildFolder\dotnet\dotnet-install.ps1" -Channel $dotnetChannel -Version 1.0.0-preview4-004233 -Architecture x64
     & "$koreBuildFolder\dotnet\dotnet-install.ps1" -Channel $dotnetChannel -Version $dotnetVersion -Architecture x64
     InstallSharedRuntime '1.1.0' 'release/1.1.0'
 

build/KoreBuild.sh

@@ -65,6 +65,8 @@ else
     chmod +x $koreBuildFolder/dotnet/dotnet-install.sh
 
     # Install the version of dotnet-cli used to compile
+    # TODO temporarily install preview4 while we move to RC3
+    $koreBuildFolder/dotnet/dotnet-install.sh --channel $KOREBUILD_DOTNET_CHANNEL --version 1.0.0-preview4-004233
     $koreBuildFolder/dotnet/dotnet-install.sh --channel $KOREBUILD_DOTNET_CHANNEL --version $KOREBUILD_DOTNET_VERSION
     install_shared_runtime '1.1.0' 'release/1.1.0'
     install_shared_runtime $sharedRuntimeVersion 'master'