(TK-369) Move java 7 to 8 in travis config because Jetty 9.4 no longer supports java 7
(TK-369) Move java 7 to 8 in travis config because Jetty 9.4 no longer supports java 7

rlinehan/trapperkeeper-webserver-jetty9,rlinehan/trapperkeeper-webserver-jetty9,camlow325/trapperkeeper-webserver-jetty9,camlow325/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9,puppetlabs/trapperkeeper-webserver-jetty9