Unable to Call MySQL from within Azure Functions v2 with .NET Core

Hi! I have a [StackOverflow issue](https://stackoverflow.com/questions/50142785/local-configuration-exception-in-azure-functions-v2-and-mysql) with additional details about what we're seeing and an open support case with Microsoft Support. They suggested creating a GitHub issue here in parallel since Azure Functions v2 is in Preview.

One additional contributor in Stack Overflow was able to reproduce the issue in his environment as well.

#### Brief Description

There seems to be a problem with the configuration system initializing when running locally in the latest version of Visual Studio 2017 and the latest version of the Azure Functions extension. Additionally, this project is using V2 of the Azure Functions platform.

#### Additional Information
Sample source code, dependencies, stack trace, exception information, and repro available on Stack Overflow at: https://stackoverflow.com/questions/50142785/local-configuration-exception-in-azure-functions-v2-and-mysql