(Flask) MySQLをherokuで使いたいが、エラーがでる

###前提・実現したいこと
flaskをherokuにデプロイしようとしているのですが、
一応はできたんですけど、SQLALCHEMYでMysqlをつなげるところがうまくいきません

やったこととしては

clearDB(Mysqlの作成)
DATABASE_URIの作成

この二つです

その後、

db.create_all()
がある__init__.pyを実行したところ

以下のようなエラーが帰ってきました

Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 1122, in _do_get
    return self._pool.get(wait, self._timeout)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/queue.py", line 145, in get
    raise Empty
sqlalchemy.util.queue.Empty

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "init_db.py", line 5, in <module>
    db.create_all()
  File "/app/.heroku/python/lib/python3.6/site-packages/flask_sqlalchemy/__init__.py", line 972, in create_all
    self._execute_for_all_tables(app, bind, 'create_all')
  File "/app/.heroku/python/lib/python3.6/site-packages/flask_sqlalchemy/__init__.py", line 964, in _execute_for_all_tables
    op(bind=self.get_engine(app, bind), **extra)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/sql/schema.py", line 3934, in create_all
    tables=tables)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1928, in _run_visitor
    with self._optional_conn_ctx_manager(connection) as conn:
  File "/app/.heroku/python/lib/python3.6/contextlib.py", line 81, in __enter__
    return next(self.gen)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1921, in _optional_conn_ctx_manager
    with self.contextual_connect() as conn:
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 2112, in contextual_connect
    self._wrap_pool_connect(self.pool.connect, None),
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 2147, in _wrap_pool_connect
    return fn()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 387, in connect
    return _ConnectionFairy._checkout(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 766, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 516, in checkout
    rec = pool._do_get()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 1138, in _do_get
    self._dec_overflow()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py", line 66, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
    raise value
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 1135, in _do_get
    return self._create_connection()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 333, in _create_connection
    return _ConnectionRecord(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 461, in __init__
    self.__connect(first_connect_check=True)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool.py", line 651, in __connect
    connection = pool._invoke_creator(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/strategies.py", line 105, in connect
    return dialect.connect(*cargs, **cparams)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 393, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "/app/.heroku/python/lib/python3.6/site-packages/pymysql/__init__.py", line 90, in Connect
    return Connection(*args, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'reconnect'

データベース関連以外は問題なく動いているので、データベースの接続のところのみの問題だと思います。
問題がありそうなところがあれば、どんなことでもいいので、教えていただけると嬉しいです。


import os
from logging import INFO

from flask.app import Flask
from flask.helpers import make_response, url_for
from flask.json import jsonify
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

app.logger.setLevel(INFO)

app.config['SQLALCHEMY_DATABASE_URI'] = os.environ['DATABASE_URL']
app.config['SECRET_KEY'] = 'f76bafcccd4c1135f37f06e818cad3cc30e6d64a3c6c6653'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

db = SQLAlchemy(app)

参考にした記事です
PostgreSQLを用いたFlaskアプリのHerokuデプロイ(Flask-SQLAlchemy)