Bug fix for "RoBERTaTensorizer object has no attribute is_input"

pytext/contrib/README.md

@@ -0,0 +1,14 @@
+# What is 'contrib' directory?
+
+Code in 'contrib' directory is considered experimental. If it's proved to be useful, we may incorporate it into the core PyText structure. The code review turnaround time for changes in 'contrib' is expected to be shorter than changes in the core PyText structure.
+
+'contrib' is organized by projects. We recommend the following directory structure to prevent file collisions:
+
+```
+  contrib/
+    my_project/     - project name
+      common/       - mimic the core PyText structure
+      config/            
+      data/
+      ...
+```

pytext/data/bert_tensorizer.py

@@ -274,6 +274,7 @@ def __init__(
         max_seq_len: int = Config.max_seq_len,
         base_tokenizer: Tokenizer = None,
     ) -> None:
+        super().__init__()
         self.columns = columns
         self.vocab = vocab
         self.tokenizer = tokenizer