Add project name, when running dead_code_detector in multiple legacy projects

when an org has multiple legacy projects, using a shared redis, 
it can be useful to build the name of the specific project into the redis key, e.g.:

```
        "dead_code_detector/record_keeper/#{project_name}/#{class_name}/class_methods"
        "dead_code_detector/record_keeper/#{project_name}/#{class_name}/instance_methods"
 ```   

