Hi,
it seems like there is a mismatch between the minimum Java version in the readme and the bytecode version in the jar in the maven repository.
At least I get an java.lang.UnsupportedClassVersionError: net/schmizz/sshj/SSHClient : Unsupported major.minor version 51.0 error when trying to instantiate the SSHClient class.
Can't say whether this is a mistake in the documentation or in the deployed jar.