Install onnx package (#1170)

http://b/235510037

Author: Philmod

Dockerfile.tmpl

@@ -511,6 +511,7 @@ RUN pip install flashtext && \
     # ipympl adds interactive widget support for matplotlib
     pip install ipympl==0.7.0 && \
     pip install pandarallel && \
+    pip install onnx && \
     /tmp/clean-layer.sh
 
 # Download base easyocr models.

tests/data/mnist-8.onnx

@@ -0,0 +1,8 @@
+import unittest
+
+import onnx
+
+class TestOnnx(unittest.TestCase):
+    def test_load(self):
+        model = onnx.load("/input/tests/data/mnist-8.onnx")
+        self.assertIn("CNTKGraph", onnx.helper.printable_graph(model.graph))