Use NUNIT_ prefix for API_KEY environment variables

[CharliePoole]

This issue was the cause of a failure in the releases of 3.16 and 3.16.1 from which I had to recover. It should be corrected in both the version3 and main branches to facilitate future work.

To retrieve Api Keys for pushing binaries, we use the following environment variables...

MYGET_API_KEY
NUGET_API_KEY
CHOCO_API_KEY

This works fine unless the developer is working on multiple projects, which use the same environment variables but need different values. That's what I was doing with NUnit and TestCentric. The problem arises in part because the above variables are used in online examples of Cake scripts.

This issue will replace the current variables with

NUNIT_MYGET_API_KEY
NUNIT_NUGET_API_KEY
NUNIT_CHOCO_API_KEY

For compatibility, we will fall back to the original environment variables if the new ones are not present.

[CharliePoole]

This issue has been resolved in version 3.16.2

The release is available on:
GitHub.
NuGet packages are also available NuGet.org and
Chocolatey Packages may be found at Chocolatey.org