Created asGraphGenerator.py that generates a graph based on the provi…

…der-customer relationships of autonomous systems stemming from the clique (#8)

* Created asGraphGenerator.py.

* Updated asGraphGenerator.py to keep track of providers and siblings for all ASes from relationships file

* Update asGraphGenerator.py to reduce code redundancy and increase readability

* Update asGraphGenerator.py to write links to the graph file

* Update asGraphGenerator.py to format entire graph file

* Update asGraphGenerator.py to generate a graph based on provider-customer and customer-provider relationships only

* Add ASN node labeling in asGraphGenerator.py

* Update asGraphGenerator.py to accept a labels file for specific labels on autonomous systems

* Update asGraphGenerator.py to allow labels file to specify attribute name and fix so that it works without any labels file

* Updated asGraphGenerator.py to use snake_case for method names

* Removed formatCodeString() method from asGraphGenerator.py

* Add format_last_value() to asGraphGenerator.py to reduce code redundancy

* Remove use of global variables in asGraphGenerator.py

* Update asGraphGenerator.py to provide a selection attribute for the specified labels

* Update asGraphGenerator.py to assign a customer to the provider with the greatest customer cone when there are multiple providers of equal greatest depth

* Create separate method for parsing customer cones in asGraphGenerator.py

* Update asGraphGenerator.py to keep track of the customers for each autonomous system

* Update formatting and wording in asGraphGenerator.py

* Update asGraphGenerator.py to graph all provider-customer relationships with the exception of autonomous systems that do not have providers and are not a part of the clique