can pass arbitrary string to java invoke now at build_cloud

examples
            h2o_hosts.build_cloud(2,java_heap_GB=4,java_extra_args='-XX:+PrintCompilation')
            h2o_hosts.build_cloud_with_hosts(java_extra_args='-XX:+PrintCompilation')
typo
Merge branch 'master' of github.com:0xdata/h2o