Added demo-examples and assignments related to control_statements and few data structures in ruby.
Merge pull request #18 from kgaikwad/day_2

Added demo-examples and assignments related to control_statements and fe...
Updated Day2 assignments
Added day2 extra assignments
Renamed file from txt to rb
Added Course Day3 demo codes
Added Day4 demo codes
Updated Day3 demo codes
Private Vs Protected demo
Day5 demo codes includes - Logger and Time Class.