avro

AVRO-2961: Support .NET 5.0 (#981)

* AVRO-2961: Use PackageIcon isntead of PackageIconUrl. PackageIconUrl is deprecated and some package repos do not support it

* AVRO-2961: Add latest dotnetcore-2.1, dotnetcore-3.1 and dotnetcore-5.0 packages to build environment

* AVRO-2961: Add netcoreapp2.1,netcoreapp3.1,net5.0 to supported frameworks

* AVRO-2961: Change framework to net 5.0

* AVRO-2961: Avoid debugging issues when caught exception is rethrown

* AVRO-2961: Replace deprecated Assembly.CodeBase with Assembly.Location

* AVRO-2961: Set default build framework to net 5.0

* AVRO-2961: Upgrade packages to latest

* AVRO-2961: Use StringBuilder.Append(char) if arg is a  one char string. Should be more optimal code. (Warning introduced by package upgrades)

* AVRO-2961: Use already existing avro-logo.png for package icon

* AVRO-2961: Update README.md with NET 5.0

* AVRO-2961: Remove rethrow exception comment

* AVRO-2961: Add netcoreapp2.1 and netcoreapp3.1 to Avro.test TargetFrameworks

* AVRO-2961: Use version.props to define used package versions, instead of hard coding in every csproj file

* AVRO-2961: Add versions.props

* AVRO-2961: Hide avro-logo.png

* AVRO-2961: Add new dependency version update strategy

* Update lang/csharp/versions.props

Co-authored-by: Brian Lachniet <blachniet@gmail.com>

* Update lang/csharp/README.md

Co-authored-by: Brian Lachniet <blachniet@gmail.com>

* Update lang/csharp/README.md

Co-authored-by: Brian Lachniet <blachniet@gmail.com>

* AVRO-2961: FxCopAnalyzers package has been deprecated in favor of Microsoft.CodeAnalysis.NetAnalyzers

Co-authored-by: Zoltan Csizmadia <CsizmadiaZ@valassis.com>
Co-authored-by: Brian Lachniet <blachniet@gmail.com>