vertex degree calculation
Added test for vertex degree calculation
Create test_vertex_degree.cpp
Create test_vertex_degree.h
find_conn_comp: work with oriented graphs and issue #5
connective component is now a graph
Merge pull request #7 from A-Green/vertex_degree

added vertex degree calculation
Merge pull request #11 from KiselN/conn-comp-fix

Connective component fix
merge