How to use the gulp-git.commit function in gulp-git

function gitCommit () {
  // commit build and package.json with updated version number
  return gulp.src([
    path.join(srcDir, '*'),
    'package.json',
    'package-lock.json'
  ]).pipe(git.commit(gitCommitMessage))
}

gulp.task('tag', function() {
    return gulp.src(['./package.json', './bower.json', './pivottable.jquery.json'])
    .pipe(git.commit('version bump'))
    // read only one file to get the version number
    .pipe(filter('package.json')) 
    .pipe(tag_version());
});

function inc(importance) {
    // get all the files to bump version in
    return gulp.src(['./manifest.json','./package.json', './bower.json'])
        // bump the version number in those files
        .pipe(bump({type: importance}))
        // save it back to filesystem
        .pipe(gulp.dest('./'))
        // commit the changed version number
        .pipe(git.commit('bumps package version'))
        // read only one file to get the version number
        .pipe(filter('manifest.json'))
        // **tag it in the repository**
        .pipe(tag_version());
}

function inc(importance) {
  // get all the files to bump version in
  return gulp.src(['./package.json', './bower.json'])
    // bump the version number in those files
    .pipe(bump({type: importance}))
    // save it back to filesystem
    .pipe(gulp.dest('./'))
    // commit the changed version number
    .pipe(git.commit('bumps package version'))

    // read only one file to get the version number
    .pipe(filter('package.json'))
    // **tag it in the repository**
    .pipe(tag_version());
}

function inc(importance) {
    // get all the files to bump version in
    return gulp.src(['./package.json'])
        // bump the version number in those files
        .pipe(bump({type: importance}))
        // save it back to filesystem
        .pipe(gulp.dest('./'))
        // commit the changed version number
        .pipe(git.commit('Bumps package version'))
        // read only one file to get the version number
        .pipe(filter('package.json'))
        // **tag it in the repository**
        .pipe(tagVersion({ prefix: '' }));
}

function gitCommit () {
  return gulp.src(['build/*', 'package.json', 'package-lock.json'])
    .pipe(git.commit(gitCommitMessage))
}

var commitIt = function (version, cb) {
        var commitMessage = "Bumps version to v" + version;
        return gulp.src('./*.json', srcConfig).pipe(git.commit(commitMessage, {cwd: rootDir}))
            .on('end', function () {
                git.push('origin', currentBranch + ':' + branch, {cwd: rootDir}, cb);
            });
    };

function tag () {
  var pkg = require('./package.json');
  var v = 'v' + pkg.version;
  var message = 'Release ' + v;

  return gulp.src('./')
    .pipe(git.commit(message))
    .pipe(git.tag(v, message))
    .pipe(git.push('origin', 'master', '--tags'))
    .pipe(gulp.dest('./'));
}

function tag () {
  var pkg = require('./package.json');
  var v = 'v' + pkg.version;
  var message = 'Release ' + v;

  return gulp.src('./')
    .pipe(git.commit(message))
    .pipe(git.tag(v, message))
    .pipe(git.push('origin', 'master', '--tags'))
    .pipe(gulp.dest('./'));
}

gulp.task("commit-changes", function() {
  return gulp.src(".")
  .pipe(git.add())
  .pipe(git.commit("chore: bump version number [ci skip]"));
});