add example with passing cmdline flags to the LAMMPS instance

test/lib_python/in.simple-001.py

@@ -1,16 +1,10 @@
 #!/usr/bin/env python -i
-# preceeding line should have path for Python on your machine
-
-# simple.py
-# Purpose: mimic operation of couple/simple/simple.cpp via Python
-# Syntax:  simple.py in.lammps
-#          in.lammps = LAMMPS input script
 
 infile = 'in.simple'
 me = 0
 
 from lammps import lammps
-lmp = lammps(cmdargs=['-echo','screen'])
+lmp = lammps()
 
 # run infile one line at a time