Migrate .NET 3.0 to .NET 3.1 (#30)

* .NET Core 3.0 support

* Updated .NET Core 2.2 project references
Updated .NET Core 2.2 Dockerfile to reference latest MS images
Migrated Quick Starts to individual projects
Moved shared test code to shared folder for reducing duplications

* .NET Core 2.2 quickstart update for JSON reference

* Removed trailing whitespace

Removed trailing whitespace

* Travis updates

Updating to xenial; dotnet sdk 3.0 install

* Download correct dpkg for .NET Core on 16.04

Didn't update it, still referenced 14.04 dpkg

* Scala formatting

Updated to match expected formatting of file ... note for self: `gradlew scalafmtAll`

* CHANGELOG Updates

Updated to reflect appropriate release and release status.

* .NET 3.0 to .NET 3.1

.NET 3.0 to .NET 3.1

* Scala Tests

Fixed test class names; added additional test for 3.1 runtime to test 2.2 project
27 files changed