docs: update basePath documentation (#655)

Author: is2ei

docs/API.md

@@ -78,7 +78,7 @@ arch [sometimes](https://code.google.com/p/selenium/issues/detail?id=5116#c9).
 
 `opts.ignoreExtraDrivers` only downloads and installs drivers explicity specified. Broken https://github.com/webdriverio/selenium-standalone/issues/421
 
-`opts.basePath` sets the base directory used to store the selenium standalone `.jar` and drivers. Defaults to current working directory + .selenium/
+`opts.basePath` sets the base directory used to store the selenium standalone `.jar` and drivers. Defaults to `node_modules/selenium-standalone/.selenium`
 
 `opts.progressCb(totalLength, progressLength, chunkLength)` will be called if provided with raw bytes length numbers about the current download process. It is used by the command line to show a progress bar.