[Test] add test data and test for CreateDataflowPartition

tests/fpgadataflow/test_create_dataflow_partition.py

+import os.path
+from pkgutil import get_data
+
+from finn.core.modelwrapper import ModelWrapper
+from finn.custom_op.registry import getCustomOp
+from finn.transformation.fpgadataflow.create_dataflow_partition import (
+    CreateDataflowPartition,
+)
+
+
+def test_create_dataflow_partition():
+    # load the onnx model
+    raw_m = get_data(
+        "finn", "data/onnx/finn-hls-model/tfc_w1_a1_after_conv_to_hls.onnx"
+    )
+    model = ModelWrapper(raw_m)
+    model = model.transform(CreateDataflowPartition())
+    assert model.graph.node[2].op_type == "StreamingDataflowPartition"
+    sdp_node = getCustomOp(model.graph.node[2])
+    assert sdp_node.__class__.__name__ == "StreamingDataflowPartition"
+    assert os.path.isfile(sdp_node.get_nodeattr("model"))