singleton-stepanov 0.3.0

Attempt to do Efficient Programming with Components: Lecture 2 Part 1, Efficient Programming with Components: Lecture 2 Part 2 and Efficient Programming with Components: Lecture 3 Part 1 from C++ to Ruts. [1] https://www.youtube.com/watch?v=FUMPsmKnKv8 [2] https://www.youtube.com/watch?v=B5yiLvaxPS4 [3] https://www.youtube.com/watch?v=sp_IBYVqMeQ