V1.7 release note (#2662)

docs/en_US/Release.md

 # ChangeLog
 
+# Release 1.7 - 7/8/2020
+
+## Major Features
+
+### Training Service
+
+* Support AML(Azure Machine Learning) platform as NNI training service.
+* OpenPAI job can be reusable. When a trial is completed, the OpenPAI job won't stop, and wait next trial. [refer to reuse flag in OpenPAI config](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/TrainingService/PaiMode.md#openpai-configurations).
+* [Support ignoring files and folders in code directory with .nniignore when uploading code directory to training service](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/TrainingService/Overview.md#how-to-use-training-service).
+
+### Neural Architecture Search (NAS)
+
+* [Provide NAS Open Benchmarks (NasBench101, NasBench201, NDS) with friendly APIs](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/NAS/Benchmarks.md).
+
+* [Support Classic NAS (i.e., non-weight-sharing mode) on TensorFlow 2.X](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/NAS/ClassicNas.md).
+
+### Model Compression
+
+* Improve Model Speedup: track more dependencies among layers and automatically resolve mask conflict, support the speedup of pruned resnet.
+* Added new pruners, including three auto model pruning algorithms: [NetAdapt Pruner](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/Pruner.md#netadapt-pruner), [SimulatedAnnealing Pruner](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/Pruner.md#simulatedannealing-pruner), [AutoCompress Pruner](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/Pruner.md#autocompress-pruner), and [ADMM Pruner](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/Pruner.md#admm-pruner).
+* Added [model sensitivity analysis tool](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/CompressionUtils.md) to help users find the sensitivity of each layer to the pruning.
+* [Easy flops calculation for model compression and NAS](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/CompressionUtils.md#model-flops-parameters-counter).
+
+* Update lottery ticket pruner to export winning ticket.
+
+### Examples
+
+* Automatically optimize tensor operators on NNI with a new [customized tuner OpEvo](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/TrialExample/OpEvoExamples.md).
+
+### Built-in tuners/assessors/advisors
+
+* [Allow customized tuners/assessor/advisors to be installed as built-in algorithms](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Tutorial/InstallCustomizedAlgos.md).
+
+### WebUI
+
+* Support visualizing nested search space more friendly.
+* Show trial's dict keys in hyper-parameter graph.
+* Enhancements to trial duration display.
+
+### Others
+
+* Provide utility function to merge parameters received from NNI
+* Support setting paiStorageConfigName in pai mode
+
+## Documentation
+
+* Improve [documentation for model compression](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/Compressor/Overview.md)
+* Improve [documentation](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/NAS/Benchmarks.md)
+and [examples](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/NAS/BenchmarksExample.ipynb) for NAS benchmarks.
+* Improve [documentation for AzureML training service](https://github.com/microsoft/nni/blob/v1.7/docs/en_US/TrainingService/AMLMode.md)
+* Homepage migration to readthedoc.
+
+## Bug Fixes
+
+* Fix bug for model graph with shared nn.Module
+* Fix nodejs OOM when `make build`
+* Fix NASUI bugs
+* Fix duration and intermediate results pictures update issue.
+* Fix minor WebUI table style issues.
+
 ## Release 1.6 - 5/26/2020
 
 ### Major Features