fix(cli): fix typo on event listener registration
wip($travis): first attempt to run slimerjs on travis
wip($travis): add SlimerJS install
wip($travis): change ln options
wip($travis): force path to slimer in the run_tests script
wip($travis): move slimer to bin instead of /usr/bin
wip($travis): try things
wip($travis): try things
chore($core): remove verbose now that three outputs are displayed each time
feat($travis): add slimerjs tests on travis