Update dependencies for 3.1.0 (#570)

## Usage and product changes
Update dependencies prior to release 3.1.0. In details:
* Update dependencies without pinned versions.
* Update the `rocksdb` crate
* Pin the version of the `cc` create to avoid breaking `rocksdb` Bazel
build.

## Motivation
Make sure that the dependencies are in a stable and non-conflicting
state

## Implementation
See comments.