Install sxs with the install-dotnet scripts (#124)

* Use dotnet-install scripts for proper sxs

* Update dotnet version in testing

* Error message cleanup

* SxS testing in the dotnet project

* Update package lock

* Test fixes

* Use proper environment variable

* Set dotnet root for windows

.gitignore

@@ -95,4 +95,5 @@ typings/
 # DynamoDB Local files
 .dynamodb/
 
-.vscode/*
+# Ignore .vscode files
+.vscode/