DMD and dub available via chocolatey

[Daniel Jost via Digitalmars-d-announce]

 From the homepage[1]: Chocolatey is a Machine Package Manager, 
somewhat like apt-get, but built with Windows in mind.

I have added dmd[2] and dub[3] as packages. This means you can do 
command line installation and have them ready to go in one step. 
I also made sure to allow users to change the version number so 
you can get non-current / beta versions as well.

If anyone would like to be added to the maintainers list (mostly 
to keep the version number up-to-date), email me and I can add 
you.

1. https://chocolatey.org/
2. https://chocolatey.org/packages/dmd
3. https://chocolatey.org/packages/dub