ActionML's PredictionIO + Universal Recommender: error building and deploying model

I installed ActionML's PredictionIO fresh following the quick install documentation at http://www.actionml.com/docs/pio_quickstart (Ubuntu linux, Elasticsearch + HBase option. Java 8 was pre-installed) . After that I followed the quick install documentation to install the Universal Recommender fresh at http://www.actionml.com/docs/ur_quickstart . The documentation says that after the git checkout I can run ./examples/integration-test . When executing integration-test I get this error

Building and delpoying model
[INFO] [Console$] Using command '/home/gustavo/PredictionIO/sbt/sbt' at the current working directory to build.
[INFO] [Console$] If the path above is incorrect, this process will fail.
[INFO] [Console$] Uber JAR disabled. Making sure lib/pio-assembly-0.9.6.jar is absent.
[INFO] [Console$] Going to run: /home/gustavo/PredictionIO/sbt/sbt  package assemblyPackageDependency
Exception in thread "Thread-0" javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1949)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)



( Note that "delpoying" is mispelled...)


This same error happened to me another day when I was also trying to install the Universal Recommender. This is a reply that I received:

"
ActionML released PredicitonIO 0.9.6 then 3 weeks later Salesforce released the same number forcing SSL and making it incompatible with the UR.

So ActionML released PIO 0.9.7-aml. We are on RC 2 now. This version is required with the UR, please see these instructions to upgrade: actionml.com/docs/install

"

However, I don't understand why I would need to "upgrade". I'm not trying to install Salesforce's PredictionIO and UR. I followed just the ActionML quick install steps. Also I don't understand why this would be an upgrade, since this is a fresh install.