inject a trait into check execution to allow unit testing

File access and command execution is now through the trait to allow
mocking input for testing.

Author: tzneal

sources/bloodhound/Cargo.toml

@@ -16,8 +16,6 @@ serde = { workspace = true, features = ["derive"] }
 serde_json.workspace = true
 serde_yaml.workspace = true
 walkdir.workspace = true
-
-[dev-dependencies]
 tempfile.workspace = true
 
 [build-dependencies]