OP: enable Resize/Prelu/Sigmoid, modified Reshape

[erizmr]

Hi @jackwish ,

The main contributions in this PR are listed below:

1. Enable three new operators: Resize, Prelu, Sigmoid(seems that Sigmoid has been developed in another pull request, sorry for this redundant work..)
2. Modified Reshape to adapt cases with one attribute
3. Produce test models for three new operators (seems the model files are list in the .gitignore, so I excluded them from this PR )

Thanks for your awesome code review in advance :)

[zhenhuaw-me]

Hi @erizmr thanks for your contribution! It seems you forget to include the TFLite model file of resize_bilinear in this PR :)

[zhenhuaw-me]

For adding TFLite model files, you may need to use git add -f {file} as *.tflite is ignored by default.

[erizmr]

Thanks! Have uploaded the missing models.

[zhenhuaw-me]

@erizmr thank you for your great contribution! I have some minor comments, and I will read the Resize part tomorrow.

Btw, would you mind helping to update the Operator Support Status to demonstrate the new ops in this PR?

[codecov]

Codecov Report

Merging #25 (c43b3bb) into master (268211b) will increase coverage by 0.18%.
The diff coverage is 95.45%.

@@            Coverage Diff             @@
##           master      #25      +/-   ##
==========================================
+ Coverage   95.13%   95.31%   +0.18%     
==========================================
  Files          26       27       +1     
  Lines        1458     1559     +101     
==========================================
+ Hits         1387     1486      +99     
- Misses         71       73       +2     

Impacted Files	Coverage Δ
tflite2onnx/op/reshape.py	91.66% <66.66%> (+0.17%)	⬆️
tflite2onnx/op/activation.py	97.00% <96.42%> (-0.27%)	⬇️
tflite2onnx/op/resize.py	98.55% <98.55%> (ø)
tflite2onnx/op/__init__.py	100.00% <100.00%> (ø)

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[zhenhuaw-me]

@erizmr Thanks for your active work on this :) I have quick look at the Resize part and left several comments, but I need some time to check the interpolation in detail still.

The Codecov requires coverage don't drop > 1% (I am not sure if it's correctly configured though...), we may try to get that.

[erizmr]

Hi @jackwish , thanks for your review! Please check again.

[zhenhuaw-me]

@erizmr LGTM in general, thanks for your contribution!