Cleanup cargo build warnings

[jbesraa]

Handle warnings generated when running cargo build, preferably in an incremental way with separate commit for each set of warnings

[rrybarczyk]

The warnings I see that need to be addressed are:

1. Cargo.toml unused manifest keys. Do we just delete the lines causing the warning? Then we lose metadata. Is there a way to properly suppress these warnings? What are best practices here?
2. Code/logic warnings like roles-utils/rpc/src/lib.rs:8:19 and jd-client/src/lib/error.rs:31:5

[Arshia-r-m]

Are these warnings generate with every cargo build or just the initial one?

[rrybarczyk]

Are these warnings generate with every cargo build or just the initial one?

Every cargo build. It is quite annoying.

[Arshia-r-m]

I want to work on this issue, I will put the updates on following comments

[jbesraa]

sure, go for it