[comprehensive] [Resource] generator for using S3 buckets

This crate provides a macro for declaring an S3 bucket as a [comprehensive::Resource]. It is a thin wrapper over the [s3::Bucket] type. When included in a [comprehensive::Assembly] it probes the bucket periodically as a health check signal.

// Defines a new type "SomeBucket" which is a Resource with
// display name "My storage". It installs command line flags
// beginning with "--app-data-" for specifying the bucket.
comprehensive_s3::bucket!(SomeBucket, "My storage", "app-data-");

// It can later be used as a dependency for another Resource:
#[derive(comprehensive::ResourceDependencies)]
struct OtherDependencies {
    bucket: std::sync::Arc<SomeBucket>,
}

Command line flags for buckets