change com.bettercloud vault driver to spring driver

[HomeOfTheWizard]

Bettercloud's library seems not continuing.
Plus its api is not very testable.
Forked project JOpenLibs might be a better choice for the future.

[HomeOfTheWizard]

We have also another option. using the spring.cloud.vault.core.
The POC below proves it can work
https://github.com/HomeOfTheWizard/spring-vault-maven-plugin

[HomeOfTheWizard]

• change vault driver library to openlibs update_vault_driver_jopenlibs #8
• refactor architecture for better testability