Move Set weight helpers to new Algorithm\Weight
Add tests with 100% code coverage for new Algorithm\Weight
Document new `Algorithm\Weight`
Fix getting minimum weight for graphs which include null weights
Merge pull request #33 from clue/move-algo-weight

Move Set weight helpers to new Algorithm\Weight
Improve documentation
Move Graph degree helpers to new Algorithm\Degree

Move `Graph::getDegree()`, `Graph::getDegreeMin()`,
`Graph::getDegreeMax()` and `Graph::isRegular()` to new
`Algorithm\Degree`
Add test with 100% coverage for new Algorithm\Degree
Document new Algorithm\Degree
Move Graph::isBalanced() to Algorithm\Degree
Improve documentation for Algorithm\Degree
Merge pull request #29 from clue/move-algo-degree

Move Graph degree helpers to new Algorithm\Degree
Move Graph balanace helpers to new Algorithm\Balance
Add tests with 100% code coverage for new Algorithm\Balance
Fix inverted logic
Document new `Algorithm\Balance`
Improve documentation
Merge pull request #30 from clue/move-algo-balance

Move Graph balance helpers to new Algorithm\Balance
Move Set directed helpers to new Algorithm\Directed
Add test with 100% coverage for new Algorithm\Directed