Updated and cleaned up Gemfile.
Installed RSpec into the project.
Installed Cucumber to the project.
Created Task model and its spec.
Generated tasks controller and appropriate specs.
Removed extra .keep files.
Added some RSpec examples for Task class.
Created the prototype for tasks list.
Integrated Bootstrap styles to tasks view.
Created test data for the list of tasks. Improved tasks table style.
Implemented the form allowing to edit the selected task.
Implemented create the new task action.
Implemented delete the task action.
Created Theme model.
Prepared initial data for investment themes.