a lot of solvable puzzles
two new tests...that are running smoothly
fixed interfaces to support looking by nodes, not indexes
Puzzles are being solved by BFS, checkout fifteen directory,
checked solvability up to 8th folder
fixed folder naming
Merge branch 'master' of github.com:kornicameister/Puzzle15

* 'master' of github.com:kornicameister/Puzzle15:
  Rapaired few bugs in strategies
  Added defined depth states generator.
  iDFS added
  DFS improvements
  Added random order generator
  Added DFS searching
  Update pom.xml