Package upgrades to support .NET Standard 2 and the new 2.x Stackexch…

…ange.Redis client

Changing min StackExchange.Redis version to 1.2.6, fixes #179

Improving backplane messaging. Reduced message size when sending mult…

…iple messages in bulks and improved de/serialization of the messages by 6-10x times

Fixing the minimum cache timeout validation #159 (it is too early...)

Removing version prefix. I'm trying to set prefix and version during …

…appveyor build now #147

Update README.md

Adding some tests for non known types, #125

using latest dev korebuild

lets try signed packages from now on... fixes #87

Update to netcoreapp deps