set working directory for nunit task.rb

nunit :unittests do |nunit|
  #you can set the working directory using nunit.command_directory - poorly named, i know. will fix that in next release.
  nunit.command_directory = "src/tests/bin/release/"

  #note: the path_to_command is relative to the working directory
  nunit.path_to_command = "../../../../nunit/nunit-console.exe"
  
  #note: the path to the assemblies is also relative to the working directory
  nunit.assemblies "tests.dll"
end