bump proxmox crate to 0.1.7

bump proxmox crate to 0.1.7

The -sys, -tools and -api crate have now been merged into
the proxmx crate directly. Only macro crates are separate
(but still reexported by the proxmox crate in their
designated locations).

When we need to depend on "parts" of the crate later on
we'll just have to use features.

The reason is mostly that these modules had
inter-dependencies which really make them not independent
enough to be their own crates.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>