feat(serverless-testing-workshop): ✨ Add C# Integration Tests

Added C# solution to `workshops/serverless-testing-workshop/tests/integration/dotnet/` as a language option for the `Testing in the Cloud` portion of the Serverless Testing workshop.

The solution demonstrates the use of:

* Skeleton project for workshop participant to use during workshop
* Completed solution for workshop participant to use in case they get stuck
* xUnit as a viable option for integration tests
* The use of xUnit [Collection Fixtures](https://xunit.net/docs/shared-context#collection-fixture) and [Class Fixtures](https://xunit.net/docs/shared-context#class-fixture)
* Using the .NET AWS SDK to obtain information about CloudFormation Stacks
* Using the .NET AWS SDK to manipulate test data in DynamoDB

Author: BradKnowles

workshops/serverless-testing-workshop/tests/integration/dotnet/.editorconfig

@@ -0,0 +1,26 @@
+# https://editorconfig.org/
+
+# What is EditorConfig?
+
+# EditorConfig helps maintain consistent coding styles for multiple developers
+# working on the same project across various editors and IDEs. The EditorConfig
+# project consists of a file format for defining coding styles and a collection
+# of text editor plugins that enable editors to read the file format and adhere
+# to defined styles. EditorConfig files are easily readable and they work nicely
+# with version control systems.
+
+# top-most EditorConfig file
+root = true
+
+[*]
+charset = utf-8
+end_of_line = crlf
+
+indent_style = tab
+indent_size = 2
+
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.cs]
+indent_size = 4