Update INSTALL.md

INSTALL.md

 
 Execute command 
 ````
-C:\Python34\python -m pip install Downloads\pygame-1.9.2a0-cp34-none-win32.whl
+C:\Python34\python -m pip install "Downloads\pygame-1.9.2a0-cp34-none-win32.whl"
 ````
 Launch Git Bash program and execute command 
 ````