Discussed fix for #147

[Glebka]

So I created a PR that implements what was discussed in #147:
I added an ability to pass Readable stream as data argument + created a test for it.

@perry-mitchell, please review.

[perry-mitchell]

Hi @Glebka - Thanks for this! Seems the tests are failing but are mostly unrelated.. That being said, I don't have time right now to find the issue.. Would there be any chance you might take a took?

Seems to be xvfb failing on web, which I can try restarting now, and seems that some dependency updated on the node side (Hapi rubbish most likely) to add ... spreading, which doesn't work on Node 6.

I'll be supporting node 6 until a new version is released - soon.

[perry-mitchell]

Ok, upon closer look I'm not sure that this will work for downstream users in the browser. I think it's best that we don't use native node modules, especially streams and other file/IO items, as they don't transpile or transpile poorly.

I'll leave this open for dicussion, but I'm not sure how we can move forward with this in its current state.

[perry-mitchell]

@Glebka I've updated the PR to include checks for the new web version, hope you don't mind. Waiting to see if the tests pass now.