Update txtai to 2.0.0 and fix breaking change

Author: davidmezzetti

setup.py

@@ -31,7 +31,7 @@
           "html2text>=2020.1.16",
           "mdv>=1.7.4",
           "tqdm==4.48.0",
-          "txtai>=1.2.0"
+          "txtai>=2.0.0"
       ],
       classifiers=[
           "License :: OSI Approved :: Apache Software License",

src/python/codequestion/evaluate.py

@@ -211,7 +211,7 @@ def test(args, embeddings):
             tokens2 = Tokenizer.tokenize(row[3])
 
             if tokens1 and tokens2:
-                score = embeddings.similarity(tokens1, [tokens2])[0]
+                score = embeddings.similarity(tokens1, [tokens2])[0][1]
                 scores.append(score)
 
                 # Ground truth score normalized between 0 - 1