remove extra empty lines

wfl/calculators/castep.py

@@ -61,13 +61,11 @@ def __init__(self, keep_files="default", rundir_prefix="run_CASTEP_",
             # make sure we are looking for pspot if path given
             kwargs["find_pspots"] = True
 
-
         # WFLFileIOCalculator is a mixin, will call remaining superclass constructors for us
         super().__init__(keep_files=keep_files, rundir_prefix=rundir_prefix,
                          workdir=workdir, scratchdir=scratchdir, **kwargs)
 
 
-
     def calculate(self, atoms=None, properties=_default_properties, system_changes=all_changes):
         """Do the calculation. Handles the working directories in addition to regular
         ASE calculation operations (writing input, executing, reading_results)