I get two errors with the latest build:

1104 [main] INFO com.datastax.driver.core.ClockFactory - Using java.lang.System clock to generate timestamps.
1245 [main] WARN com.datastax.driver.core.NettyUtil - Found Netty's native epoll transport in the classpath, but epoll is not available. Using NIO instead.
java.lang.NoClassDefFoundError: io/netty/channel/epoll/EpollDatagramChannel$DatagramSocketAddress
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1941)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1824)
at java.lang.Runtime.load0(Runtime.java:809)
at java.lang.System.load(System.java:1086)

and

2447 [main] INFO org.reflections.Reflections - Reflections took 46 ms to scan 2 urls, producing 0 keys and 0 values
4790 [main] WARN org.apache.tinkerpop.gremlin.server.GremlinServer - Graph [graph] configured at [conf/gremlin-server/janusgraph-cassandra-es-server.properties] could not be instantiated and will not be available in Gremlin Server. GraphFactory message: GraphFactory could not instantiate this Graph implementation [class org.janusgraph.core.JanusGraphFactory]
java.lang.RuntimeException: GraphFactory could not instantiate this Graph implementation [class org.janusgraph.core.JanusGraphFactory]
at org.apache.tinkerpop.gremlin.structure.util.GraphFactory.open(GraphFactory.java:82)