Lint using clippy

src/broadcaster.rs

src/import_contest.rs

src/main.rs

src/models/submission.rs

src/models/user.rs

src/pages/create_contest.rs

src/pages/create_submission.rs

src/pages/get_contest_scoreboard_by_id.rs

src/pages/get_problems.rs

src/pages/get_submissions.rs

src/pages/mod.rs

src/pages/prelude.rs

src/setup.rs