Addressing issues reported by flake8.

Author: madpah

cyclonedx/output/json.py

@@ -1,5 +1,4 @@
 import json
-from abc import ABC, abstractmethod
 
 from . import BaseOutput
 from .schema import BaseSchemaVersion, SchemaVersion1Dot0, SchemaVersion1Dot1, SchemaVersion1Dot2, SchemaVersion1Dot3
@@ -12,7 +11,7 @@ def output_as_string(self) -> str:
         return json.dumps(self._get_json())
 
     def output_to_file(self, filename: str):
-        raise NotImplemented
+        raise NotImplementedError
 
     def _get_json(self) -> dict:
         components = list(map(self._get_component_as_dict, self.get_bom().get_components()))

cyclonedx/output/schema.py

@@ -1,4 +1,4 @@
-from abc import ABC, abstractmethod
+from abc import ABC
 
 
 class BaseSchemaVersion(ABC):

cyclonedx/output/xml.py

@@ -24,7 +24,7 @@ def output_as_string(self) -> str:
         return Xml.XML_VERSION_DECLARATION + ElementTree.tostring(bom, 'unicode')
 
     def output_to_file(self, filename: str):
-        pass
+        raise NotImplementedError
 
     def _component_supports_bom_ref_attribute(self) -> bool:
         return True