Add sqlitedict dependency

requirements.txt

@@ -4,4 +4,5 @@ datasets>=1.2.1
 click>=7.1
 scikit-learn>=0.24.1
 torch>=1.7
-transformers>=4.1
\ No newline at end of file
+transformers>=4.1
+sqlitedict==1.6.0
\ No newline at end of file