Fix: NEventStore#30 fixed assembly version numbers, fixed NEventStore…

… reference,

fixed Appveyor build scripts and NuGet packages.

Updated csproj file to include package informations

Fixed AssemblyInfo.cs, it was not used by the new build scripts, removed

unused files

updated Appveyor script

Updated changelog

Updated NEventStore submodule to version 7.0.0, changed NuSpec file

Marked as Explicit and Changed unsupported scenario test to different…

…iate between net45,

net451, netstandard2.0 behaviors. Tests has been marked as Explicit
because they have different behavior in local machines and Appveyor,
they need further investigation

Updated NEventStore to 6.0.0, updated Nuspec and testing libraries

Merge branch 'release/6.0.0-rc-0'