Cracking The Coding Interview template and tests

Currently there are only solutions and not many tests. Uses gtest and cmake to build.

Progress

• Arrays - done but needs more tests
• LinkedList - done but needs more tests
• Stack - done but needs more test
• Graph - in progress
• ........

Contribution

• For new questions make sure the code works and readable.
• For existing questions new tests would be much appretiated.