1. I've managed all the includes properly so there is nothing declared
twice or missing something.
2. In Manager.h there were mistake. It was private twice, so I changed all
the members to be public.
3. Employee.cpp and Employee.h were no body of the getName() function, so
I've added it.
4. In the Employee constructor when memory allocation happen has to be
added +1 to handle NULL termination character.