Onnxcli

What's Changed
* Ping onnxoptimizer to 0.2.7 due to "Unresolved value references" issue. See more in https://github.com/zhenhuaw-me/onnxcli/issues/28
* convert: enable onnx to json by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/10
* inspect: print input and output tensor too by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/12
* inspect: dump input output tensor by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/14
* inspect: show dimension name instead of value if has any by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/17
* draw: gen tensor info for tensors that only have name by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/18
* setup: install the dependent python packages by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/19
* Check command by zhenhuaw-me in https://github.com/zhenhuaw-me/onnxcli/pull/21


**Full Changelog**: https://github.com/zhenhuaw-me/onnxcli/compare/v0.2.0...v0.2.1

* inspect: fix several bugs and render issue.
* draw: now support duplicate names of tensor and node
* optimize: use onnxoptimizer as backend
* update online help and docs.

**Full Changelog**: https://github.com/jackwish/onnxcli/compare/v0.1.0...v0.2.0

* infershape: Run Shape Inference on given ONNX model
* extract: Extract sub model with given input and output tensor names.
* inspect: Prints the information of nodes tensors of the given model
* draw: Draw the graph with the given ONNX model. Save you from Netron.
* update docs