Even if ‘windows’ was supported, the sheer size required to have a setup that builds the engine (VisualStudio alone…) is too big for a free service on top of bitbucket or github (Travis CI) most likely.
You can take a look at Appveyor https://www.appveyor.com, they specialise in CI on Windows, with VisualStudio setups etc. To get the result of your build, you will have to pay for a license though.