Wrote test to check that any live cell with fewer than two live neighbours dies.
Implemented copy constructor to perform a deep copy of the game grid.
Effective C++ Item 3: Use const whenever possible.
Merge branch 'master' of https://github.com/kwkhaw/TddExercise
Revert "Merge branch 'master' of https://github.com/kwkhaw/TddExercise"

This reverts commit 2bb15390f32d555ff9f10e81353203f059c16e5e, reversing
changes made to 2774d1640399a3bd381f41af23513e3f53b199c9.
- change absolute path to relative path.