make installation procedure consistent with install.py

python/setup.py

@@ -1,7 +1,8 @@
 # this only installs the LAMMPS python package
 # it assumes the LAMMPS shared library is already installed
 from distutils.core import setup
-import os
+from sys import version_info
+import os,time
 
 LAMMPS_PYTHON_DIR = os.path.dirname(os.path.realpath(__file__))
 LAMMPS_DIR = os.path.dirname(LAMMPS_PYTHON_DIR)
@@ -12,7 +13,13 @@ def get_lammps_version():
         line = f.readline()
         start_pos = line.find('"')+1
         end_pos = line.find('"', start_pos)
-        return "".join(line[start_pos:end_pos].split())
+        t = time.strptime("".join(line[start_pos:end_pos].split()), "%d%b%Y")
+        return "{}.{}.{}".format(t.tm_year,t.tm_mon,t.tm_mday)
+
+if version_info.major >= 3:
+    pkgs = ['lammps', 'lammps.mliap']
+else:
+    pkgs = ['lammps']
 
 setup(
     name = "lammps",
@@ -22,5 +29,5 @@ setup(
     url = "https://lammps.sandia.gov",
     description = "LAMMPS Molecular Dynamics Python package",
     license = "GPL",
-    packages=["lammps","lammps.mliap"],
+    packages=pkgs,
 )