Changed to "is" when comparing types

Author: seanlaw

stumpy/core.py

@@ -429,11 +429,11 @@ def check_dtype(a, dtype=np.float64):  # pragma: no cover
     TypeError
         If the array type does not match `dtype`
     """
-    if dtype == int:
+    if dtype is int:
         dtype = np.int64
-    if dtype == float:
+    if dtype is float:
         dtype = np.float64
-    if dtype == bool:
+    if dtype is bool:
         dtype = np.bool_
     if not np.issubdtype(a.dtype, dtype):
         msg = f"{dtype} dtype expected but found {a.dtype} in input array\n"