Add new packages for next release

[mulkieran]

The new packages are:

• stratisd_proc_macros for sure
• devicemapper-rs-sys almost certainly

It looks like we can not avoid packaging stratisd-proc-macros:

1. For crates.io
2. For Fedora

We should get this done weeks before we start packaging stratisd, in order to give ourselves lead time to do more work on stratisd packaging. At present, we can not build an rpm of stratisd on Fedora due to the stratisd-proc-macro crate not being available yet.

It would be nice if we could just release it as part of the stratisd crate, but I believe that is not possible. Presumably this is because the compilation of the macros must be staged before the compilation of the stratisd crate. Requiring the macros to be a whole separate crate still seems a bit overkill; why not just force the compilation in a build script?

[mulkieran]

I filed an issue upstream: rust-lang/cargo#9826.

[mulkieran]

We should release devicemapper-rs-sys as soon as bindgen and nix versions are bumped in Fedora.

We want bindgen bumped to 0.59 because of stratis-storage/devicemapper-rs#690.
We would like to bump nix because of #349.

Other than that, the library is completely by the numbers, and not likely to change much, basically at all, other than by dependency updates.

[mulkieran]

upstream bz for stratisd-proc-macros: https://bugzilla.redhat.com/show_bug.cgi?id=2015224

[mulkieran]

All sub-issues completed.