message: update README.md for mac build
  for mac only supporting pkg build.
diff: @@ -32,7 +32,7 @@ In order to achieve those goals Symphony is participating and working in close c
  ## Build Instructions:
  - npm install
  - to run locally: npm run dev
  -- to build mac dmg: npm run dist-mac
  +- to build mac pkg: npm run unpacked-mac, then run: /usr/local/bin/packagesbuild -v installer/mac/symphony-mac-packager.pkgproj. You'll need to have packages installed: http://s.sudre.free.fr/Software/Packages/resources.html
  - to build win msi: npm run unpacked-win (for 64 bit) and use 'advanced installer' .aip file in installer/ dir
  ## msi command line options:
  