Syntax error when running `npm run build`.

[nicholassm]

Hi Benoit,

I can't seem to get it to run on Mac OS Sierra - I must admit I'm not very experienced in using Node.js.
Maybe the wrong version of Babel? Or?

➜  halftone git:(master) ✗ npm run build

> halftone@0.1.1 build /Users/xxx/code/halftone
> rm -rf dist/* && babel src --ignore __tests__ --out-dir dist

SyntaxError: src/index.js: Unexpected token, expected { (17:7)
  15 | 
  16 | 
> 17 | export type Options = {
     |        ^
  18 |  /**
  19 |  * Size of the output image
  20 |  */

npm ERR! Darwin 16.3.0
npm ERR! argv "/usr/local/Cellar/node/7.4.0/bin/node" "/usr/local/bin/npm" "run" "build"
npm ERR! node v7.4.0
npm ERR! npm  v4.0.5
npm ERR! code ELIFECYCLE
npm ERR! halftone@0.1.1 build: `rm -rf dist/* && babel src --ignore __tests__ --out-dir dist`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the halftone@0.1.1 build script 'rm -rf dist/* && babel src --ignore __tests__ --out-dir dist'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the halftone package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     rm -rf dist/* && babel src --ignore __tests__ --out-dir dist
npm ERR! You can get information on how to open an issue for this project with:
npm ERR!     npm bugs halftone
npm ERR! Or if that isn't available, you can get their info via:
npm ERR!     npm owner ls halftone
npm ERR! There is likely additional logging output above.