Publish graph-from-ascii separately

Hey, looked through the code and I like how you can quickly visualize a graph in ascii and have it created for you. So please publish [this](https://github.com/anvaka/ngraph.path/blob/master/test/utils/graphFromAscii.js) as a module that anyone could use.

Great work with this lib BTW .. I'm sure it'll come in useful for something I need some day.

Start with test/utils/graphFromAscii.js, the file named in the issue, and inspect the repository's package metadata and public entry points to understand how a separate module would be published. Done means graph-from-ascii is available as an independently consumable module rather than only as a test utility.

Written by the indexing model from the issue text.