Support Vault 0.10

[CYBAI]

In vault 0.10, there're some prefix between mounted path and the secret search path. When upgrading from vault 0.9 to vault 0.10, we should separate them for secret engine v2.

(@bitc I'd like to update the unit test if current implementation is fine. Thanks!)

[bitc]

Thanks for this pull request. Could you please explain in one or two more sentences what this pull request does and why it's needed?

Also, will this break support for vault versions 0.9 and lower?

Thanks

[CYBAI]

Hi @bitc , thanks for confirmation about the change. Let me answer the second question first.

Also, will this break support for vault versions 0.9 and lower?

I think Yes, it would break the support of vault version 0.9 and lower. After vault 0.10, the KV secret engine v2 will be default. But, for 0.9 or other lower versions, it would be v1.

Ref: https://www.vaultproject.io/docs/secrets/kv/index.html#kv-version-2

Could you please explain in one or two more sentences what this pull request does and why it's needed?

So, this PR aims to support KV secret engine v2 that there're some difference in endpoint.

Operation	Difference
Read	There is only difference in path.
List	There is only difference in path.
Create/Update	Difference in path and new version uses POST for both update and create operations. + for v2 payload should be wrapped into "data" object.
Remove	Difference in path.

(Note: This table is copied from spring-projects/spring-vault#242)

• KV Secret Engine V1 document: https://www.vaultproject.io/api/secret/kv/kv-v1.html
• KV Secret Engine V2 document: https://www.vaultproject.io/api/secret/kv/kv-v2.html

[alexbiehl]

@bitc @CYBAI What is the status on this one?

[CYBAI]

@bitc ping for review

[bitc]

I've merged this. let me know if anyone needs me to release a new hackage version