Standardize build scripts for extensions

[CharliePoole]

The extension build scripts have evolved independently so they are somewhat uneven.Although they work well, it would be convenient for maintenance of the extensions if they were reasonably parallel.

The current "ideal" CI script would use the following:

• Use of loaded cake files such that the same name is used for the same purpose in each project
• Use of typed Cake context in most tasks (BuildParameters)
• Use of GitVersion to determine build version
• Inclusion of package tests using multiple console versions
• Publication of dev packages to myget
• Publication of production packages to nuget and chocolatey
• Creation of draft and final releases on GitHub
• Ability to run publication and release steps independently in case a re-run is needed.

The nunit project loader scripts will be reviewed to see which of the above items need to be added.

[CharliePoole]

Status of the NUnit Project Loader package...

• [x] Separate cake files
• [x] Typed cake context
• [x] Use GitVersion
• [x] Package Tests
• [x] Publish dev packages
• [x] Publish production packages
• [x] Create GitHub draft and final releases
• [ ] Independent rerun of publication and release steps

[CharliePoole]

Last two steps will be done as separate issues

[CharliePoole]

:tada: This issue has been resolved in version 3.7.1 :tada:

The release is available on:

• GitHub Release
• NuGet Package
• Chocolatey Package