The CI/CD build is broken

[liuq]

I tried to contribute with a PullRequest but according to the CI/CD log the build is broken. The message, for your convenience, is the following:

Build started
[2](https://ci.appveyor.com/project/BenLauwens/resumablefunctions-jl/builds/46004858#L2)git clone -q https://github.com/BenLauwens/ResumableFunctions.jl.git C:\projects\resumablefunctions-jl
[3](https://ci.appveyor.com/project/BenLauwens/resumablefunctions-jl/builds/46004858#L3)git fetch -q origin +refs/pull/58/merge:
[4](https://ci.appveyor.com/project/BenLauwens/resumablefunctions-jl/builds/46004858#L4)git checkout -qf FETCH_HEAD
[5](https://ci.appveyor.com/project/BenLauwens/resumablefunctions-jl/builds/46004858#L5)The build phase is set to "MSBuild" mode (default), but no Visual Studio project or solution files were found in the root directory. If you are not building Visual Studio project switch build mode to "Script" and provide your custom build command.

[Krastanov]

Fixed in #62