Add project.ignore to the config keys

Summary: We are going to need this to deal properly with ignore paths, so lets start collecting it.

Reviewed By: aniketmathur

Differential Revision: D57542260

fbshipit-source-id: 0bee38dc89b37ffc4c684446d620c82f72b18ff3

audit/src/lib.rs

@@ -58,6 +58,7 @@ pub fn audit_config_arguments() -> &'static [&'static str] {
         "--all-cells",
         "buildfile.name",
         "buildfile.name_v2",
+        "project.ignore",
         REUSE_CONFIG,
     ]
 }