nuget and license

[Stephen Mallette <sp...@gmail.com>]

While doing the release I saw this warning message from nuget:

     [echo] nuget.exe already downloaded.
     [exec] Pushing Gremlin.Net.3.2.11.nupkg to '
https://www.nuget.org/api/v2/package'...
     [exec]   PUT https://www.nuget.org/api/v2/package/
     [exec] WARNING: <licenseUrl> element will be deprecated,please
consider switching to specifying the license in the package. Learn more:
https://aka.ms/deprecateLicenseUrl.
     [exec]   Created https://www.nuget.org/api/v2/package/ 1475ms
     [exec] Your package was pushed.
     [exec] Pushing Gremlin.Net.Template.3.2.11.nupkg to '
https://www.nuget.org/api/v2/package'...
     [exec]   PUT https://www.nuget.org/api/v2/package/
     [exec] WARNING: <licenseUrl> element will be deprecated,please
consider switching to specifying the license in the package. Learn more:
https://aka.ms/deprecateLicenseUrl.
     [exec]   Created https://www.nuget.org/api/v2/package/ 1826ms
     [exec] Your package was pushed.

After some reading I opted to fix it with this:

https://github.com/apache/tinkerpop/commit/fa0afb574d5eed68cd389764dbcce72d13f18ba2

I dont' think we need to reference our copy of the Apache LICENSE because
that is the TinkerPop source license and not the binary license. Since this
specific .NET stuff is convenience binary related I think we can just go
with the vanilla SPDX license identifiers. If this wasn't the way to
resolve these warnings, please let me know if something else should have
been done. Thanks.