Added dotenv loading

.gitignore

@@ -1 +1,2 @@
-constants.py
+constants.py
+*.env*

app.py

@@ -1,6 +1,7 @@
 import os
 import sys
 import openai
+from dotenv import load_dotenv, find_dotenv
 import gradio as gr
 from langchain.chains import ConversationalRetrievalChain, RetrievalQA
 from langchain.chat_models import ChatOpenAI
@@ -11,9 +12,7 @@ from langchain.indexes.vectorstore import VectorStoreIndexWrapper
 from langchain.llms import OpenAI
 from langchain.vectorstores import Chroma
 
-import constants
-
-os.environ["OPENAI_API_KEY"] = constants.APIKEY
+load_dotenv(find_dotenv())
 
 # Enable to save to disk & reuse the model (for repeated queries on the same data)
 PERSIST = False