[Bug] electron download electron-chromedriver version mismatch

[matrixbirds]

reproduce steps:
set 5.0.8 electron in package.json and set ELECTRON_CUSTOM_DIR.

expect: It still download chrome-driver 5.0.0, It should be also specified the fixed version to download electron chrome-driver.
actual: It still download 5.0.0 chrome driver version.
I suggest to change the version download logical, with ELECTRON_CUSTOM_DIR.
https://github.com/electron/chromedriver/blob/3807adbf7adbb4f778dcb35999e99dbf90760d41/download-chromedriver.js#L30