Add configurable options for Ping Check and SSLMode

[quentinkhoo]

This PR enables the following configuration options through the config file:

Postgres

• sslmode: allows you to configure the sslmode for the connection string
• pingCheck: allows you to confgiure whether a ping check should be performed before establishing the DB connection

MySQL

• pingCheck: allows you to confgiure whether a ping check should be performed before establishing the DB connection

[quentinkhoo]

hey @klouddb , i've made a PR in reference to the issues highlighted in this issue, let me know if the PR works or where it can be improved! :)