Allow passing options to recast about jscodeshift

[jamischarles]

Appears to be related to #4

[jamischarles]

Ah, just saw that this is possible. This would be great to add to the readme :)

.toSource({quote:'single'})

[wincent]

This would be great to add to the readme

Would you like to have a crack at that in a PR?

[fkling]

I assume this can be closed then?

[jamischarles]

Yep. Thx!

[NefeliSylvia]

Hi everyone! how can i get the source map? i assumed i need write something like

var root = jscodeshiftAPI(code,{sourceFileName: fileName});
//write transformations
result = root.toSource({sourceMapName: "map.json"});

but result doesn't have the .map property