Refactor: extract fn try_consume_file

The main purpose of this change is to make the following commits more
readable.

src/documents/consumer.py

@@ -75,20 +75,22 @@ class Consumer:
         docs_old_to_new = sorted(docs, key=lambda doc: os.path.getmtime(doc))
 
         for doc in docs_old_to_new:
+            self.try_consume_file(doc)
 
+    def try_consume_file(self, doc):
         doc = os.path.join(self.consume, doc)
 
         if not os.path.isfile(doc):
-                continue
+            return
 
         if not re.match(FileInfo.REGEXES["title"], doc):
-                continue
+            return
 
         if doc in self._ignore:
-                continue
+            return
 
         if not self._is_ready(doc):
-                continue
+            return
 
         if self._is_duplicate(doc):
             self.log(
@@ -96,14 +98,14 @@ class Consumer:
                 "Skipping {} as it appears to be a duplicate".format(doc)
             )
             self._ignore.append(doc)
-                continue
+            return
 
         parser_class = self._get_parser_class(doc)
         if not parser_class:
             self.log(
                 "error", "No parsers could be found for {}".format(doc))
             self._ignore.append(doc)
-                continue
+            return
 
         self.logging_group = uuid.uuid4()
 
@@ -132,7 +134,7 @@ class Consumer:
             self.log("error", "PARSE FAILURE for {}: {}".format(doc, e))
             parsed_document.cleanup()
 
-                continue
+            return
 
         else: