Added Unit Test for the HashTable example
Added .gitignore for the tests folder
Added unit tests of the JsonArray example
Added unit tests of sample string given by gbatree
Added unit tests for all members of the gbathree JSON string
Added unit tests on multi-dimensional arrays to isolate the bug
Fixed null pointer exception in JsonArray and JsonHashTable constructors
Added unit tests for invalid arrays
Added more test on arrays
Fixed the bug in getNestedTokenCount()
Refactored getNestedTokenCount()