Upgrade the required version for flatbuffers. (#2050)

* Allow all versions >= 1.12 to be installed.

Signed-off-by: Jay Zhang <[email protected]>

setup.py

@@ -82,7 +82,7 @@ def run(self):
     author='ONNX',
     author_email='[email protected]',
     url='https://github.com/onnx/tensorflow-onnx',
-    install_requires=['numpy>=1.14.1', 'onnx>=1.4.1', 'requests', 'six', 'flatbuffers~=1.12'],
+    install_requires=['numpy>=1.14.1', 'onnx>=1.4.1', 'requests', 'six', 'flatbuffers>=1.12'],
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Intended Audience :: Developers',