Mind Graph Improvements

[vdpappu]

• Update Edge properties to capture article/meeting frequency
• Change the edge/node names to reflect what they capture
• Upgrade single nouns to key-phrases wherever applicable
• Address Plural forms of nodes
• Address Entity Key-phrase(small case) entities

[vdpappu]

@ArjunKini Consider this filteration too
http://10.190.208.9:7000/user/venkat/notebooks/home/venkat/hdd/Venkat/key_phrase_extract_score/mixed_graph_test/explore_mixed_graph.ipynb