Updated world.rank

import rank is deprecated
Changed lines 10 and 614 to use world.rank "from ase.parallel import world"

catlearn/optimize/mlneb.py

@@ -7,7 +7,7 @@
 from ase.neb import NEBTools
 from ase.io import read, write
 from ase.optimize import MDMin
-from ase.parallel import parprint, rank, parallel_function
+from ase.parallel import parprint, world, parallel_function
 from scipy.spatial import distance
 import os
 from catlearn.regression import GaussianProcess
@@ -611,7 +611,7 @@ def run(self, fmax=0.05, unc_convergence=0.050, steps=500,
  parprint('The optimized predicted path can be found in: ',
  trajectory)
  # Clean up:
- if rank == 0:
+ if world.rank == 0:
  os.remove('./last_predicted_path.traj')
  os.remove('./all_predicted_paths.traj')
  break