Cargo workspaces support

[l4l]

Currently, if cargo-rpm launched from within the workspace root the following error is printed:

error: no [package] section in Cargo.toml!

As I may guess, the workspaces are not supported and for now it's just possible to iterate over necessary crates manually and for each execute cargo rpm build. Would be nice, if it supported from cargo-rpm itself. List of possible subtasks:

• new command cargo rpm list that lists projects that has a (valid) .rpm sub-folder at that workspace;
• executing cargo rpm init at workspace root inits .rpm for each crate in that workspace, optionally with specified crate list;
• executing cargo rpm build at workspace root builds each crate in a workspace (optionally) skipping ones without .rpm sub-folder;
• flag -p/--package for selecting a package to work with (i.e. cargo rpm -p mypackage build works the same as changing directory to mypackage package and then launching cargo rpm build).

[tony-iqlusion]

This sounds like a good plan

[tony-iqlusion]

cargo-rpm is unmaintained: #96