chore: delete unncessary AtomicTable comments.

Author: stevenhua0320

src/diffpy/structure/parsers/p_vesta.py

@@ -35,12 +35,8 @@
 from diffpy.structure.parsers.p_xcfg import AtomicMass
 from diffpy.structure.structureerrors import StructureFormatError
 
-# Constants ------------------------------------------------------------------
-
-# Atomic Mass of elements
-# This can be later when PeriodicTable package becomes available.
-
 
+# Constants ------------------------------------------------------------------
 class P_vesta(StructureParser):
     """Parser for VESTA native structure format (.vesta).