ScriptExecutor tests refactoring
Fixes scriptcs/scriptcs#375 - line splitting when linebreaks differ between Host and file
Update NuGet from v2.2.1 to v2.6.1
Run package restore as a separate build step
Copy assemblies produced by the build to the artifacts directory
Merge pull request #378 from jrusbatch/issues/357

Copy assemblies to artifacts directory after build.
Merge pull request #376 from stirno/filesystem-fix

Fixes scriptcs/scriptcs#375 - line splitting when linebreaks differ
Merge pull request #372 from lbargaoanu/References

ScriptExecutor tests refactoring