Fix ServiceStack sample by moving packages into named "packages" folder

Service stack currently fails with error:
Unhandled Exception: System.IO.DirectoryNotFoundException: Could not find a part
 of the path 'C:\Source\scriptcs\samples\servicestackhost\packages'.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemEnumerableIterator`1.CommonInit()
   at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String origina
lUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`
1 resultHandler, Boolean checkHost)
   at System.IO.Directory.EnumerateFiles(String path, String searchPattern, Sear
chOption searchOption)
   at Scriptcs.PackageAssemblyResolver.GetAssemblyNames() in c:\Source\scriptcs\
src\Scriptcs\PackageAssemblyResolver.cs:line 26
   at Scriptcs.Program.Main(String[] args) in c:\Source\scriptcs\src\Scriptcs\Pr
ogram.cs:line 37

Moving the ServiceStack packages into "packages" folder fixes this.