Add remove method to StorageBackendInterface

Define a remove method for removing/deleting items from the storage
backend. The tuf reference implementation needs to be able to delete
metadata files which have been marked as removed.

Signed-off-by: Joshua Lock <[email protected]>

Author: joshuagl

securesystemslib/storage.py

@@ -93,6 +93,25 @@ def put(self, fileobj, filepath):
     raise NotImplementedError # pragma: no cover
 
 
+  @abc.abstractmethod
+  def remove(self, filepath):
+    """
+    <Purpose>
+      Remove the file at 'filepath' from the storage.
+
+    <Arguments>
+      filepath:
+        The full path to the file.
+
+    <Exceptions>
+      securesystemslib.exceptions.StorageError, if the file can not be removed.
+
+    <Returns>
+      None
+    """
+    raise NotImplementedError # pragma: no cover
+
+
   @abc.abstractmethod
   def getsize(self, filepath):
     """