* 1.0
- Start release from course 21-22 code.
* 1.1
- Removed template parameter E for WEdge. Fixed to float type.
* 2.0
- Rewrite api.
- Added iterators.
- Added ctest support.
* 2.1
- Standardizing iterators.
* 2.2
- Remove visited flag from edges and update related documentation and tests.
* 2.2.1
- Fixed bug. Add set_item method to graph.
