feat: push checkout (#14)

Reviewed-on: https://git.reya.su/reya/signed/pulls/14

crates/signed_core/src/lib.rs

@@ -1,7 +1,6 @@
 pub mod addr;
 pub mod annotations;
 pub mod clone_url;
-pub mod comments;
 pub mod deletions;
 pub mod filters;
 pub mod model;
@@ -11,7 +10,6 @@ pub mod status;
 pub use addr::{RepoAddr, identifier_from_name, repo_addr};
 pub use annotations::{COVER_NOTE_KIND, cover_note, labels_and_subject, subject_override};
 pub use clone_url::{CloneTarget, parse_clone_url};
-pub use comments::{CommentThread, comment_threads};
 pub use deletions::Deletions;
 pub use model::{Announcement, activity_subject, pull_request_patch, pull_request_patches};
 pub use state::{build_state, parse_state};