Added support for CI via Travis.
Added support for CI via Travis.

esteve/ros2_java,esteve/ros2_java,Theosakamg/ros2_java,Theosakamg/ros2_java,esteve/ros2_java,esteve/ros2_java,Theosakamg/ros2_java,Theosakamg/ros2_java,Theosakamg/ros2_java,esteve/ros2_java