Update GuardClauses.csproj with new version and release notes

Update GuardClauses.csproj

Update GuardClauses.csproj

Updating version to 3.0 since we are changing to netstandard2.0

Updating version to 3.0 since we are changing to netstandard2.0

In Enum, OutOfRange should throw InvalidEnumArgumentException (ardali…

…s#78)

* update to netstandard2.1

* OutOfRange should throw an InvalidEnumArgumentException instead of an ArgumentOutOfRangeException for enum

* Apply InvalidEnumArgumentException to GuardClauseExtensions.

* Use netstandard2.0 insted of netstandard2.1.

* change to windows-latest in build.yml

* Package version updated.

update to include icon when packing

Update GuardClauses.csproj

Update GuardClauses.csproj

adding support for ValidatedNotNullAttrib (ardalis#60)