added index page

main.py

-from flask import Flask, abort, request
+from flask import Flask, abort, request, render_template
 from auth import auth_facebook, auth_slack
 from config import *
@@ -12,6 +12,11 @@ cfg = {
 }
+@app.route('/')
+def index():
+	return render_template('index.html')
+
+
 @app.route('/callback/xE4sA', methods=['GET', 'POST'])
 def callback():
 	if not request.json or 'type' not in request.json: