Create car class

* Takes make, model, year, and msrp as parameters
* Sets constant depreciation
* Allows manager to set markup
* Calculates value based off depreciation and markup
Add more specificity to variables
Create used car class that inherits from car class

* Add mileage depreciation
Add test applications for cars and used cars
Create a damage class

* Takes description and cost as parameters
Refactor to add depreciated value method

* Changes age depreciation value to just age depreciation
* Add depriciation value to subtract depreciation from msrp
Refactor code to have separate depreciation methods

* Method for each depreciation
* Create depreciation value method to reduce from original msrp
Add application for damaged car
Add ceiling to make prices cleaner
Create car lot class

* Initialize with a name
* Has method to add a car
* Has method to return lot value
Create a car lot creation test application
Change class variables to class constants
Add retrieval functionality to car lot class

* Stores cars in a hash with a nested hash
* Retrieves based off nested hash keys
Update create car lot app for increased functionality
Add sold functionality to car and car lot classes
Update create car lot app for sold functionality
Change variable name depreciated_value to just value
Add lot value functionality to car lot class