Set specific MySQL version to avoid SequelPro issues.

mysql/README.md

@@ -21,10 +21,3 @@ While inside the shell, run the following:
 ```
 CREATE DATABASE mydatabase;
 ```
-## Using SequelPro?
-
-You might get a `Authentication plugin 'caching_sha2_password' cannot be loaded` error. If that's the case, [enter the MySQL shell](#enter-the-mysql-shell) and run the following command: 
-
-```mysql
-ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'password'
-```

mysql/docker-compose.yml

@@ -2,7 +2,7 @@ version: '3'
 
 services: 
   db:
-    image: mysql:latest
+    image: mysql:5.7.21
     volumes:
       - dbdata:/var/lib/mysql
     restart: always