Adding base classes of the api
Resolving namespaces issues and adding base for unit tests
Adding test for inserting edges without vertices in graph
Adding graph constructions option and removing methods
Exceptions for vertices and edges and fixing minor issues with add/remove methods in graph
Adding BaseContainer implementation of IContainer

BaseContainer provides an IContainer for the creation of edges objects that did not receive one explicitly in constructor overload
Adding neighbors methods for a node in graph
Adding equality comparison for Edge type and test added

Methods implemented:
GetHashCode (override from Object)
Equals (from IEquatable<T>)
Equals (override from Object)
operator == (override from Object)
operator != (override from Object)
Renaming variables and adding test class for edges
Adding methods for inserting path and cycles

Methods:
- AddPath
- AddCycle
Solving namespace issue for class GraphTest

It had still the older namespace of previos project
Merge branch 'graph' into dev