* pcl_conversion to ros2
* travis for ros2 and fixed cmakelists
* exporting dependencies
* updated travis
* fixed smaller things
* added colcon ignore to meta package
* merge pcl_conversions.h with version released in Dashing
* merge test script, CMakeListst, package.xml
* append authors, clean up
* PR feedback
* fixed PR comments
* fixed PR comments, cmakelists message_filters, reverted type masq, added maintainer
* removed dashing and made ros_distro matrix env
