[js] Move the Builder class to the main module and remove the builder module.

The builder module was originally added to avoid a circular dependency that no
longer exists.

Author: jleyba

javascript/node/selenium-webdriver/CHANGES.md

@@ -1,3 +1,11 @@
+## v3.0.0-beta-2
+
+### API Changes
+
+* Moved the `builder.Builder` class into the main module (`selenium-webdriver`).
+* Removed the `builder` module.
+
+
 ## v3.0.0-beta-1
 
 * Allow users to set the agent used for HTTP connections through