* Replace manual electron-to-chromium list and function with external library
* test fixtures for electron: Switch to electron 1.4, with known chrome version and update expected output
* update tests: electron 1.0 used chrome 49, not 50
* import only the relevant function from electron-to-chromium
* electron fixtures: Use number instead of string
* If both chrome and electron are defined, choose the lower version to preserve
* Add to test cases to verify correct handling of chrome number