Update array flatten solution.
Merge branch 'master' of github.com:blakeembrey/code-problems

* 'master' of github.com:blakeembrey/code-problems:
  change proper variable name and clean the4 space in unit test
  1.improving delete when BST dealing with root 2.fix style 3.more unit testing for BST
  1. fix style.
  1. improving delete when BST dealing with root node. 2. modify avoid using call and apply style
  1. format the code
  1. add search and delete in binary search tree 2. add unittest for binary search tree
  update copyright year
  clean extra line
  use space instead of tab.
  clean code as advised.
  change javascript solution for binary-search-tree-check.js by using In-Order Traversal method.
  Add Insertion-sort to Sorting Algorithms list
  Add insertion-sort problem
  Add insertion-sort and associated test
  function + minimised reverse-words-in-string solution
  PHP solution for reverse words in strings