Remove unused import from operations.rs tests; expose git hooks

The git pre-commit and pre-push commit hooks weren't checking for unused
imports in tests.

I've fixed that, and exposed the pre-commit and pre-push hooks in
scripts/git-hooks

scripts/git-hooks/pre-commit

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -e
+cargo fmt -- --check
+cargo test -q
+cargo clippy --workspace --tests --examples --no-deps
+cargo clippy --profile=test
+cargo clippy --profile=release --tests --examples --no-deps

scripts/git-hooks/pre-push

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -e
+export RUSTDOCFLAGS=-Dwarnings
+cargo fmt -- --check
+cargo test -q
+cargo clippy --workspace --tests --examples --no-deps
+cargo clippy --profile=test
+cargo clippy --profile=release --tests --examples --no-deps
+cargo doc --workspace --no-deps --document-private-items

src/operations.rs

@@ -511,7 +511,6 @@ impl<Sifted: Bookkeeping, Logged: Loggable> Loggable for SiftLog<Sifted, Logged>
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::operands;
     use bstr::ByteSlice;
     use indexmap::IndexMap;
 
@@ -531,8 +530,6 @@ mod test {
         String::from_utf8(answer).unwrap()
     }
 
-    use self::OpName::*;
-
     #[test]
     fn given_a_single_argument_all_most_ops_return_input_lines_in_order_without_dups() {
         let arg: Vec<&[u8]> = vec![b"xxx\nabc\nxxx\nyyy\nxxx\nabc\n"];
@@ -647,7 +644,6 @@ mod test {
 #[allow(clippy::pedantic)]
 mod test_bookkeeping {
     use super::*;
-    use std::fs::File;
 
     #[test]
     fn line_count_update_with_uses_saturating_increment() {