Starting to add configurations and executor modules
Fixing obvious issues with configurations and executor
Replaced option_resolve with just the string formatter class
having VALID_EXTENSIONS was a bit redundant
Making it possible to not resolve with root stack config as well
Tests for CloudCityError
Starting to add configurations tests
Adding tests for ConfigReader
Starting to add tests for Configurations
Seperating Configurations into ConfigurationFinder and ConfigurationResolver
Finishing tests for ConfigurationResolver
Simplifying stack layers
Renaming StackLayers to just Layers
Starting to add Stack resolution codez