UnixClient fails sporadically on Darwin

[headius]

The example UnixClient appears to fail sporadically on Darwin. This frequently happens during release builds, but exactly once followed by a success. It could be a simple filesystem cleanup issue.

jnr-unixsocket/src/test/java/jnr/unixsocket/example/UnixClient.java

Line 46 in f61210a

UnixSocketChannel channel = UnixSocketChannel.open(address);

    [INFO] --- exec-maven-plugin:1.4.0:exec (execute) @ jnr-unixsocket ---
    Exception in thread "main" java.io.IOException: No such file or directory
    	at jnr.unixsocket.UnixSocketChannel.doConnect(UnixSocketChannel.java:130)
    	at jnr.unixsocket.UnixSocketChannel.connect(UnixSocketChannel.java:139)
    	at jnr.unixsocket.UnixSocketChannel.open(UnixSocketChannel.java:68)
    	at jnr.unixsocket.example.UnixClient.main(UnixClient.java:46)

[headius]

Note this is not to be confused with the example UnixClient in #93.