Hi Joel Barbosa,
you are missing org.jboss.shrinkwrap.resolver:shrinkwrap-resolver-impl-maven-archive on classpath. Unless you want to tune dependencies, I'd recommend to load whole SWR stack via depchain. More details here:
I'd also recommend to use 2.2.0-beta-1, it contains a lot of bugfixes when compared with 2.1.0 and very limited API changes are expected.