(pylint) minor cleaing

patacrep/tools/__init__.py

@@ -10,4 +10,4 @@ def existing_file(name):
     """
     if os.path.isfile(name) and os.access(name, os.R_OK):
         return name
-    raise argparse.ArgumentTypeError("Cannot read file '{}'.".format(name))
+    raise argparse.ArgumentTypeError("Cannot read file '{}'.".format(name))

patacrep/tools/content/__main__.py

@@ -7,7 +7,6 @@ import sys
 import textwrap
 import yaml
 
-from patacrep import errors
 from patacrep.songbook import open_songbook
 from patacrep.build import Songbook
 from .. import existing_file