Upgrade to Spring Vault 2.0.0 M2.
Upgrade to Spring Vault 2.0.0 M2.

Closes gh-141.

spencergibb/spring-cloud-vault-config,spring-cloud-incubator/spring-cloud-vault-config,spencergibb/spring-cloud-vault-config,spring-cloud-incubator/spring-cloud-vault-config