For PSD.js, publish dist folder instead of CoffeeScript for portability

[lancejpollard]

This will fix #287 I think, or something like this.

[lancejpollard]

Had to do this to resolve errors such as:

ERROR in ./lib/psd/blend_mode.coffee
Module build failed (from ./node_modules/coffee-loader/dist/cjs.js):
CoffeeScriptError: ./psd.js/lib/psd/blend_mode.coffee:43:5: error: Can't reference 'this' before calling super in derived class constructors
    @blendKey = null
    ^
    at Object.loader (./psd.js/node_modules/coffee-loader/dist/index.js:33:14)
 @ ./lib/psd/layer/blend_modes.coffee 3:12-43
 @ ./lib/psd/layer.coffee 71:17-54
 @ ./lib/psd/layer_mask.coffee 7:8-33
 @ ./lib/psd.coffee 34:12-46

[lancejpollard]

I'm getting {} when logging Psd from import Psd from '@lancejpollard/psd' when I try this, so not sure, any recommendations after seeing what my PR tries to do?