add bert base class and restructure encoding extractor

.travis.yml

@@ -48,8 +48,8 @@ before_script:
 - python -m pliers.support.download
 - python -m spacy download en_core_web_sm
 script:
-- py.test pliers/tests/test_* pliers/tests/converters pliers/tests/filters --cov=pliers --cov-report= -m "not requires_payment" -W ignore::UserWarning
-- py.test pliers/tests/extractors --cov=pliers --cov-report= -m "not requires_payment" --cov-append -W ignore::UserWarning
+  - py.test pliers/tests/test_* pliers/tests/converters pliers/tests/filters --cov=pliers --cov-report= -m "not requires_payment" -W ignore::UserWarning
+  - py.test pliers/tests/extractors --cov=pliers --cov-report= -m "not requires_payment" --cov-append -W ignore::UserWarning
 after_success:
 - coveralls
 before_cache:

pliers/extractors/__init__.py

@@ -64,7 +64,9 @@
                    NumUniqueWordsExtractor, PartOfSpeechExtractor,
                    WordEmbeddingExtractor, TextVectorizerExtractor,
                    VADERSentimentExtractor, SpaCyExtractor,
-                   WordCounterExtractor, PretrainedBertEncodingExtractor)
+                   WordCounterExtractor, BertExtractor,
+                   BertSequenceEncodingExtractor, BertLMExtractor,
+                   BertSentimentExtractor)
 from .video import (FarnebackOpticalFlowExtractor)
 
 __all__ = [
@@ -139,7 +141,10 @@
     'BeatTrackExtractor',
     'HarmonicExtractor',
     'PercussiveExtractor',
+    'BertExtractor',
+    'BertSequenceEncodingExtractor',
+    'BertLMExtractor',
+    'BertSentimentExtractor',
     'AudiosetLabelExtractor',
-    'PretrainedBertEncodingExtractor',
     'WordCounterExtractor'
 ]