message: don't use `master` as hg bookmark name
diff: @@ -306,7 +306,7 @@ test('gets changed files for hg', async () => {
  .sort(),
  ).toEqual(['file1.txt', 'file4.txt']);
  - run(`${HG} bookmark master`, DIR);
  + run(`${HG} bookmark main`, DIR);
  // Back up and develop on a different branch
  run(`${HG} checkout --rev=-2`, DIR);
  @@ -317,9 +317,9 @@ test('gets changed files for hg', async () => {
  run(`${HG} commit -m "test4"`, DIR);
  ({changedFiles: files} = await getChangedFilesForRoots(roots, {
  - changedSince: 'master',
  + changedSince: 'main',
  }));
  - // Returns files from this branch but not ones that only exist on master
  + // Returns files from this branch but not ones that only exist on main
  expect(
  Array.from(files)
  .map(filePath => path.basename(filePath))
  