This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Are you asking if there is a command in Maven to be able to do the equivalent of "update to head"? If so, what version control system are you using? Most likely there is a plugin for Maven for your version control system that provides such a function.
Note that in most development environment, developers working in an IDE will use IDE tools, and not Maven, to update to head. In addition, a continuous integration system, such as Jenkins, will be used to extract latest source from head in the version control system before invoking Maven to build the sources that were extracted. Therefore, extracting sources from version control is typically not something done in Maven.