Supress mypy error re. scipy

Scipy does not seem to have any typing. As I add type hints
to the code, I ought to create stubs for the one scipy function
I use.

earth_model/earth_model.py

@@ -6,7 +6,7 @@
 """
 
 import numpy as np
-import scipy.integrate as spint
+import scipy.integrate as spint  # type: ignore
 
 from . import peice_poly as pp