update install instruction

Author: Ruilong Li

README.md

@@ -5,7 +5,12 @@ Pytorch based data streamer. (Capture, Video & Image).
 ## Install
 
 ```
+# via pip
 pip install git+https://github.com/Project-Splinter/streamer_pytorch --upgrade
+# via git clone
+git clone https://github.com/Project-Splinter/streamer_pytorch
+cd streamer_pytorch
+python setup.py --develop
 ```
 
 ## Usage