Postman-problems

Pins `networkx` to **2.0**, as **2.1** introduced some backwards incompatible API changes (See 60).

**Features:**

- Adds Rural Postman algorithm (for graphs where required edges form a single connected component when optional edges are removed)
- Simplifies CLI API
- Adds Star RPP example
- Adds Sleeping Giant RPP example
- Postman solution summary of route
- Adds plotting for base graph with edge attributes (distance)
- Simplifies eulerian circuit to use keys of MultiGraph (feature added in Networkx 2.0)
- Updates README with new API, examples, etc

* Updating to networkx 2.0 which introduced some backwards incompatible API changes. Postman_problems release 0.1 will work on earlier < 2.0 networkx versions (i.e. 1.11, etc)
* Updating docs to RST to render nicely on PyPI
* README tweaks
* updated README w PyPI download instructions now that package is uploaded to PyPI

Hello World release.

Contains tools to solve and visualize the Chinese Postman Problem. Two examples are provided (Seven Bridges and Sleeping Giant).

See `README.md` for more details.