Merge cubano-webdriver-manager into cubano-webdriver

[nigelcharman]

From @andrew-sumner:

I’d still like to merge Cubano-webdriver-manger into Cubano-webdriver now that the licencing is resolved, we had discussed this some time ago but I cannot remember what we decided.

[nigelcharman]

My response:

Probably makes sense.

The alternative, looking ahead to Java 9 and modules, would be to view cubano-webdriver as a service interface with cubano-webdriver-manager as a service implementation. We'd then want the SauceLabs and BrowserStack classes to be in a different module too.

I'd be happy to merge them all into one for now, and then tackle how to package in Java 9 at a later date. What we might want to think about now, would be to use different packages for the implementations to keep it cleaner when we do split them out.