add support for node 6

[ranyitz]

Summary

This PR Fixes #64 and adds node 6 support

• Add a build script that runs babel and transpile all files from lib to dist
• Add dist to .gitignore
• Add dist & index.js to the files array in package.json so they will be available on next publish.
• Add an index.js file on the root, which routes between lib and dist according to the user's Node version.
• Configure Travis to run on both Node 6 and 8
• Promisified a part of the tests. I started by using babel-register but then I realized that I couldn't test that they actually run on node 6.
• Update readme

Test Plan

All tests are passing on CI when using Node 6

[lukeed]

IMO we should add a promise-based solution manually. Babel always makes a mess of async rewrites, or at least embeds a sizable runtime/mapper.

Manual rewrite would be much simpler to maintain than the sync version tbh.

Also, you never want to use stage-* anymore. Tip comes from Babel team. Stages change too often and typically only want an item or two from the set.

Not a fan of the dynamic require personally. Users should be explicit in what they use, just like tiny-glob/sync.

Just my thoughts while on the go~

[terkelg]

Thanks for the review Luke. Is async/await the only thing we need Babel for at the moment? If so, I agree a manual rewrite would be preferable

[ranyitz]

@lukeed @terkelg, async await is not the only thing, you're also using object-rest-spread which is part of stage-3 preset (moved to stage 4 though). I removed the usage in stage-2 in favor of using this specific plugin only.

Manual rewrite would be much simpler to maintain than the sync version tbh.

There is no sync version, this PR is only about supporting Node 6 without changing any behavior.

[lukeed]

Don't mind me 🙃 Reviewing while grocery shopping is bad idea. I thought I was getting emails about the tiny-glob repo 🤦‍♂️

[terkelg]

Thanks @ranyitz! I'll have a look tonight