Remove obselete test mapping file

Change-Id: I71bbf08716bc21e5cf0a2d969694c6f99487f5cd
diff --git a/TEST_MAPPING b/TEST_MAPPING
deleted file mode 100644
index 2f7de78..0000000
--- a/TEST_MAPPING
+++ /dev/null
@@ -1,13 +0,0 @@
-// Generated by update_crate_tests.py for tests that depend on this crate.
-{
-  "presubmit": [
-    {
-      "name": "libcert_request_validator_tests"
-    }
-  ],
-  "presubmit-rust": [
-    {
-      "name": "libcert_request_validator_tests"
-    }
-  ]
-}