Rewrite the publish nuget packages script

As a part of #152 :

We have pretty basic .\CodeJam\Build\BuildScripts\CodeJam.Main.Push.bat
I'd prefer to have a script (or may be a release pipeline) that will build the project with specified project version and will publish a preview version of the package.

I have no strong opinion on how on how to implement the issue. Feel free to propose ideas and may ber even an implementation!)