Update README to clarify the IPEX version and PyTorch

Update the IPEX version in setup.py to 1.2.0

Author: EikanWang

README.md

@@ -15,6 +15,15 @@ Intel Extension for PyTorch is a Python package to extend official PyTorch. It i
 ## Installation
 
 ### Install PyTorch from Source
+ |IPEX Version|PyTorch Version|
+ |--|--|
+ |[v1.2.0](https://github.com/intel/intel-extension-for-pytorch/tree/v1.2.0)|[v1.7.0](https://github.com/pytorch/pytorch/tree/v1.7.0 "v1.7.0")|
+ |[v1.1.0](https://github.com/intel/intel-extension-for-pytorch/tree/v1.1.0)|[v1.5.0-rc3](https://github.com/pytorch/pytorch/tree/v1.5.0-rc3 "v1.5.0-rc3")|
+ |[v1.0.2](https://github.com/intel/intel-extension-for-pytorch/tree/v1.0.2)|[v1.5.0-rc3](https://github.com/pytorch/pytorch/tree/v1.5.0-rc3 "v1.5.0-rc3")|
+ |[v1.0.1](https://github.com/intel/intel-extension-for-pytorch/tree/v1.0.1)|[v1.5.0-rc3](https://github.com/pytorch/pytorch/tree/v1.5.0-rc3 "v1.5.0-rc3")|
+ |[v1.0.0](https://github.com/intel/intel-extension-for-pytorch/tree/v1.0.0)|[v1.5.0-rc3](https://github.com/pytorch/pytorch/tree/v1.5.0-rc3 "v1.5.0-rc3")|
+
+ Take Intel-Extension-for-Pytorch v1.2.0 as the example.
 
  1. Get PyTorch v1.7.0 source(Refer to [PyTorch guide](https://github.com/pytorch/pytorch#get-the-pytorch-source) for more details)
     ```bash

setup.py

@@ -99,7 +99,7 @@ def get_git_head_sha(base_dir):
 
 
 def get_build_version(ipex_git_sha):
-  version = os.getenv('TORCH_IPEX_VERSION', '1.1.0')
+  version = os.getenv('TORCH_IPEX_VERSION', '1.2.0')
   if _check_env_flag('VERSIONED_IPEX_BUILD', default='0'):
     try:
       version += '+' + ipex_git_sha[:7]