Update README.md，deepCR依赖pytorch，添加进去。

README.md

@@ -4,13 +4,13 @@ detect cosmic rays and mask them
 
 # 软件依赖
 
-依赖的python包numpy, scipy, matplotlib, astropy, ccdproc, deepCR
+依赖的python包numpy, scipy, matplotlib, astropy, ccdproc, pytorch, deepCR
 
 Ubuntu 20.04系统下安装方法
 
 sudo apt install python3-numpy python3-scipy python3-matplotlib python3-astropy python3-ccdproc
 
-python3 -m pip install deepCR
+python3 -m pip install pytorch deepCR
 
 # 使用方法