taskr: target structure is not correct when passing `file` as param to task

i hope i am not doing something wrong,

this issue #200 was fixed and works perfectly now, but when using fly-babel if you dont pass file as param to the task function babel will transpile all files in path.

As i understood from the doc watch file should be passed, and it works great now babel only transpile the passed file, but the same problem in the referenced issue above occurs again.

here is my code

const paths = {
    scripts: ['./src/**/*.js']
}

export default async function () {
    await this.watch(paths.scripts, `babel`);
}

export async function babel(file) {
    await  this.source(file || paths.scripts)
        .babel({
            presets: [["es2015", {"modules": false}], "stage-1", "stage-3"],
            plugins: ["transform-es2015-modules-commonjs",
                ['transform-runtime', {
                    "polyfill": false,
                    "regenerator": true
                }]
            ],
            sourceMaps: true
        })
        .target(`./dist`);
 }