Add smoke tests for drift (#1658)

Author: AlonsoGuevara

tests/fixtures/min-csv/config.json

@@ -124,6 +124,10 @@
             "query": "What is the major conflict in this story and who are the protagonist and antagonist?",
             "method": "global"
         },
+        {
+            "query": "What is the main theme of the story?",
+            "method": "drift"
+        },
         {
             "query": "Who is Jordan Hayes?",
             "method": "basic"

tests/fixtures/text/config.json

@@ -141,6 +141,10 @@
             "query": "What is the major conflict in this story and who are the protagonist and antagonist?",
             "method": "global"
         },
+        {
+            "query": "What is the main theme of the story?",
+            "method": "drift"
+        },
         {
             "query": "Who is Jordan Hayes?",
             "method": "basic"