Bug fix to Vault Tokens

There is a conflict between vals and the vals-operator when setting up the VAULT_AUTH_METHOD variable causing both vals-operator and vals to perform login every time the controller refreshes a secret. This release rewrites the HaschiCorp Vault code to avoid conflict.

What's Changed

• Correct chart version number by @digiserg in #29
• Bugfix: kubernetes login creates too many tokens by @digiserg in #32

Full Changelog: v0.5.0...v0.6.0