Replace ACTIONHERO_TEST_FILE_EXTENSION with ACTIONHERO_TYPESCRIPT_MODE (boolean) (#1668)
Replace ACTIONHERO_TEST_FILE_EXTENSION with ACTIONHERO_TYPESCRIPT_MODE (boolean) (#1668)

* Replace ACTIONHERO_TEST_FILE_EXTENSION with ACTIONHERO_TYPESCRIPT_MODE (boolean)

* clarify logic
actionhero/actionhero,actionhero/actionhero,actionhero/actionhero,actionhero/actionhero