[AUR-395, AUR-415] Adopt Example1 Injury pipeline; add .flow() for enabling bottom-up pipeline execution (#32)

* add example1/injury pipeline example
* add dotenv
* update various api

tests/test_post_processing.py

@@ -30,9 +30,11 @@ def test_is_batch(regex_extractor):
 
 def test_run_raw(regex_extractor):
     output = regex_extractor("This is a test. 123")
+    output = [each.text for each in output]
     assert output == ["123"]
 
 
 def test_run_batch_raw(regex_extractor):
     output = regex_extractor(["This is a test. 123", "456"])
+    output = [[each.text for each in batch] for batch in output]
     assert output == [["123"], ["456"]]