Add SPIFF to API

Author: putnokiabel

trackpy/api.py

@@ -24,5 +24,6 @@
 from . import predict
 from . import utils
 from . import artificial
+from . import spiff
 from .utils import handle_logging, ignore_logging, quiet
 from .try_numba import try_numba_jit, enable_numba, disable_numba