Chore: Explicit vaultclient version
Chore: Explicit vaultclient version

Currently S3's code uses vaultclient API version 0.x, but is not
compatible with future versions. Problem: vaultclient is going to
release a new major version (which means its API has breaking changes).

In order to avoid problems, let's explicit the `0.0.1` dependency in
`package.json`.

tomateos/S3,truststamp/S3,tomateos/S3,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote,lucisilv/Silviu_S3-Antidote,truststamp/S3,tomateos/S3,tomateos/S3,scality/S3,tomateos/S3,tomateos/S3,lucisilv/Silviu_S3-Antidote,scality/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,scality/S3,scality/S3,scality/S3,scality/S3,lucisilv/Silviu_S3-Antidote,truststamp/S3,tomateos/S3,truststamp/S3,truststamp/S3,lucisilv/Silviu_S3-Antidote,scality/S3,truststamp/S3,tomateos/S3,scality/S3