Merging with Jack's changes

Merge branch 'binheap' of https://github.com/caderache2014/data_structures
Merge branch 'master' of https://github.com/caderache2014/data_structures
Merge branch 'weighted' of https://github.com/caderache2014/data_structures into weighted# Please enter a commit message to explain why this merge is necessary,# especially if it merges an updated upstream into a topic branch.## Lines starting with '#' will be ignored, and an empty message aborts# the commit.Adding the weighting
Merge branch 'weighted' of https://github.com/caderache2014/data_structures into weighted
Insignifcant changes to binaryTree.ipynb and test_heap.py