Program 5 - Rhyming Dictionary (v.0.2)

Changelog:
- Switched to input parsing using “>>” instead of getline to allow for
parsing of any word size rather than limiting to 50 char. See
createDictionary().
- Fixed a memory leaks for inputString in createDictionary()
- Added two functions to deallocate memory used to create the entire
dictionary.
- Moved the filename variable to main() and pass as an argument to
createDictionary instead. Makes it easier for user to change when
needed.
- Tested program on Linux server using Valgrind. All allocated memory
is freed.

Next: Implement user input and output the rhyming words.