point to global.js in build but not in package.json

[mickmcgrath13]

this: https://github.com/bitovi/funcunit/blob/master/package.json#L67 should be:

"main": "funcunit",

..and then add

system: {
 main: "global"
}

to outputs.global in https://github.com/bitovi/funcunit/blob/master/build.js