Automatic token and native fencing GCP

!! This version introduces some changes in the conf.yaml and drop old apiver support !!

What's Changed

• Remove machine type default from AWS by @mpagot in #261
• Drop conf.yaml apiver support by @mpagot in #262
• Add az_key_name support at glue script level only by @mpagot in #263
• Move token generation to Ansible by @BillAnastasiadis in #264
• Use vm_size in AWS modules by @mpagot in #265
• Run aws set_facts conditionally by @BillAnastasiadis in #266
• Harmonize Terraform across different CSP by @mpagot in #267
• Remove vm_size default in Azure by @mpagot in #268
• Terraform gcp vm size internal variables by @mpagot in #270
• Add documentation for Ansible SAS Token generation by @BillAnastasiadis in #269
• Enable GCP native fencing by @BillAnastasiadis in #271

Full Changelog: v0.30.0...v0.31.0