title: How to use webdriver-manager clean to remove all downloaded files?
body: <p>After every run i wish to delete all files that webdriver-manager downloaded as webdriver-manager start fails in subsequent runs inside proxy network. 
  When i run webdriver-manager clean command in console it works fine but when the same command is run via nodejas it throws an error</p>
  
  <p>command : npm run driver-clean
  script: driver-clean: 'webdriver-manager clean'
  Error : Error: EPERM: operation not permitted, unlink 'C:\mithun\ui-automation\node_modules\protractor\node_modules\webdriver-manager\selenium\chromedriver
  _75.0.3770.140.exe'</p>