1. Use webdriver-manager update
2. Gecko driver is not getting downloaded.
3. Getting the following error.

C:\Users\adhithya.srinivasan>webdriver-manager update
[16:22:19] I/config_source - curl -oC:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium\standalone-response.xml https://selenium-release.storage.googleapis.com/
[16:22:19] I/config_source - curl -oC:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium\chrome-response.xml https://chromedriver.storage.googleapis.com/
[16:22:19] I/config_source - curl -oC:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium\gecko-response.json https://api.github.com/repos/mozilla/geckodriver/releases
[16:22:20] I/downloader - curl -oC:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium/chromedriver_2.45.zip https://chromedriver.storage.googleapis.com/2.45/chromedriver_win32.zip
[16:22:21] I/downloader - curl -oC:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium/selenium-server-standalone-3.141.59.jar https://selenium-release.storage.googleapis.com/3.141/selenium-server-standalone-3.141.59.jar
[16:22:23] I/update - chromedriver: unzipping chromedriver_2.45.zip
[16:22:25] E/downloader - undefined
[16:22:25] I/update - geckodriver: file exists C:\Users\adhithya.srinivasan\AppData\Roaming\npm\node_modules\protractor\node_modules\webdriver-manager\selenium\geckodriver-v0.24.0.zip
[16:22:25] I/update - geckodriver: unzipping geckodriver-v0.24.0.zip
(node:11752) UnhandledPromiseRejectionWarning: Invalid filename
(node:11752) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:11752) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.