Fix warning with numpy 17.x+ (#2482)

This commit integrates upstream changes into TensorBoard’s
`tensorflow_stub` to resolve a deprecation warning in recent release
candidates for NumPy.

Upstream bug: <tensorflow/tensorflow#30427>

Upstream fix: <tensorflow/tensorflow#30559>

tensorboard/compat/tensorflow_stub/dtypes.py

@@ -538,16 +538,16 @@ def size(self):
 # quantized types.
 # TODO(mrry,keveman): Investigate Numpy type registration to replace this
 # hard-coding of names.
-_np_qint8 = np.dtype([("qint8", np.int8, 1)])
-_np_quint8 = np.dtype([("quint8", np.uint8, 1)])
-_np_qint16 = np.dtype([("qint16", np.int16, 1)])
-_np_quint16 = np.dtype([("quint16", np.uint16, 1)])
-_np_qint32 = np.dtype([("qint32", np.int32, 1)])
+_np_qint8 = np.dtype([("qint8", np.int8)])
+_np_quint8 = np.dtype([("quint8", np.uint8)])
+_np_qint16 = np.dtype([("qint16", np.int16)])
+_np_quint16 = np.dtype([("quint16", np.uint16)])
+_np_qint32 = np.dtype([("qint32", np.int32)])
 
 # _np_bfloat16 is defined by a module import.
 
 # Custom struct dtype for directly-fed ResourceHandles of supported type(s).
-np_resource = np.dtype([("resource", np.ubyte, 1)])
+np_resource = np.dtype([("resource", np.ubyte)])
 
 # Standard mappings between types_pb2.DataType values and numpy.dtypes.
 _NP_TO_TF = frozenset(