Added gpt-3.5-turbo 0613 16k and 16k-0613 pricing (#6287)

@agola11 

Issue
#6193 

I added the new pricing for the new models.

Also, now gpt-3.5-turbo got split into "input" and "output" pricing. It
currently does not support that.

langchain/callbacks/openai_info.py

@@ -5,21 +5,33 @@ from langchain.callbacks.base import BaseCallbackHandler
 from langchain.schema import AgentAction, AgentFinish, LLMResult
 
 MODEL_COST_PER_1K_TOKENS = {
+    # GPT-4 input
     "gpt-4": 0.03,
     "gpt-4-0314": 0.03,
-    "gpt-4-completion": 0.06,
-    "gpt-4-0314-completion": 0.06,
+    "gpt-4-0613": 0.03,
     "gpt-4-32k": 0.06,
     "gpt-4-32k-0314": 0.06,
+    "gpt-4-32k-0613": 0.06,
+    # GPT-4 output
+    "gpt-4-completion": 0.06,
+    "gpt-4-0314-completion": 0.06,
+    "gpt-4-0613-completion": 0.06,
     "gpt-4-32k-completion": 0.12,
     "gpt-4-32k-0314-completion": 0.12,
-    "gpt-4-0613": 0.06,
-    "gpt-4-32k-0613": 0.12,
-    "gpt-3.5-turbo": 0.002,
-    "gpt-3.5-turbo-0301": 0.002,
-    "gpt-3.5-turbo-16k": 0.004,
-    "gpt-3.5-turbo-0613": 0.002,
-    "gpt-3.5-turbo-16k-0613": 0.004,
+    "gpt-4-32k-0613-completion": 0.12,
+    # GPT-3.5 input
+    "gpt-3.5-turbo": 0.0015,
+    "gpt-3.5-turbo-0301": 0.0015,
+    "gpt-3.5-turbo-0613": 0.0015,
+    "gpt-3.5-turbo-16k": 0.003,
+    "gpt-3.5-turbo-16k-0613": 0.003,
+    # GPT-3.5 output
+    "gpt-3.5-turbo-completion": 0.002,
+    "gpt-3.5-turbo-0301-completion": 0.002,
+    "gpt-3.5-turbo-0613-completion": 0.002,
+    "gpt-3.5-turbo-16k-completion": 0.004,
+    "gpt-3.5-turbo-16k-0613-completion": 0.004,
+    # Others
     "text-ada-001": 0.0004,
     "ada": 0.0004,
     "text-babbage-001": 0.0005,
@@ -43,7 +55,9 @@ def standardize_model_name(
     model_name = model_name.lower()
     if "ft-" in model_name:
         return model_name.split(":")[0] + "-finetuned"
-    elif is_completion and model_name.startswith("gpt-4"):
+    elif is_completion and (
+        model_name.startswith("gpt-4") or model_name.startswith("gpt-3.5")
+    ):
         return model_name + "-completion"
     else:
         return model_name