Add building and container recipes

[the-mr-dave]

GitLab username: enoghadd

Submission of the cmake-exercise

• modified the main.cpp
• added a Dockerfile for building the container and importing the dependencies
• additionally the yaml version is set to 0.6.3 (hopefully)
• added and setted the CMakeLists.txt file to get the dependencies right

[MakisH]

Everything looks good here and works, thanks!