rule: fmt: add trailing newline to capa files

capa/rules.py

@@ -561,7 +561,7 @@ class Rule(object):
 
         ostream = six.BytesIO()
         yaml.dump(definition, ostream)
-        return ostream.getvalue().decode('utf-8').rstrip("\n")
+        return ostream.getvalue().decode('utf-8').rstrip("\n") + "\n"
 
 
 def get_rules_with_scope(rules, scope):

scripts/capafmt.py

@@ -47,7 +47,7 @@ def main(argv=None):
         with open(args.path, 'wb') as f:
             f.write(rule.to_yaml().encode('utf-8'))
     else:
-        print(rule.to_yaml())
+        print(rule.to_yaml().rstrip("\n"))
 
     return 0