Extending basic graph formation

[ajeetdsouza]

Description

add_nodes should be renamed to add_nodes_from and add_edges should be made add_edges_from to provide familiarity to NetworkX users migrating from Python. Additionally, support for remove_node, remove_nodes_from, remove_edge and remove_edges_from should be provided.

However, the graph format must be finalised first (please see the issue referenced).

• Relevant Issues : Support for basic graph formation #8
• Relevant PRs : (optional)
• Type of issue :
  • User mode :
    • Installation
    • Feature request
    • Bug in existing feature
  • Developer mode :
    • Code quality
    • Tests
    • Documentation

[universato]

Done!
I added alias (remove_nodes_from and remove_edges_from)
Graph has also add_nodes_from and add_edges_from.