distribute example data along GNPy

I would like to create a package for distribution to PIP, and this seems
like the path of least resistance.

This is, apparently, the way for shippign arbitrary data with Python
[1]. I've at least tried to make it user-firendly via adding a simple
utility which just prints out whatever that data path is.

[1] https://python-packaging.readthedocs.io/en/latest/non-code-files.html

Change-Id: I220ecad84b1d57d01e3f98f15befc700bd97c0b8

gnpy/example-data/write_path_jsontocsv.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""
+write_path_jsontocsv.py
+========================
+
+Reads JSON path result file in accordance with the Yang model for requesting
+path computation and writes results to a CSV file.
+
+See: draft-ietf-teas-yang-path-computation-01.txt
+"""
+
+from argparse import ArgumentParser
+from pathlib import Path
+from json import loads
+from gnpy.tools.json_io import load_equipment
+from gnpy.topology.request import jsontocsv
+
+
+parser = ArgumentParser(description='A function that writes json path results in an excel sheet.')
+parser.add_argument('filename', nargs='?', type=Path)
+parser.add_argument('output_filename', nargs='?', type=Path)
+parser.add_argument('eqpt_filename', nargs='?', type=Path, default=Path(__file__).parent / 'eqpt_config.json')
+
+if __name__ == '__main__':
+    args = parser.parse_args()
+
+    with open(args.output_filename, 'w', encoding='utf-8') as file:
+        with open(args.filename, encoding='utf-8') as f:
+            print(f'Reading {args.filename}')
+            json_data = loads(f.read())
+            equipment = load_equipment(args.eqpt_filename)
+            print(f'Writing in {args.output_filename}')
+            jsontocsv(json_data, equipment, file)