minor: Use topic_name() in travis test.
minor: Use topic_name() in travis test.

brainwane/zulip,andersk/zulip,andersk/zulip,brainwane/zulip,zulip/zulip,punchagan/zulip,rht/zulip,kou/zulip,hackerkid/zulip,timabbott/zulip,punchagan/zulip,timabbott/zulip,brainwane/zulip,kou/zulip,showell/zulip,zulip/zulip,rishig/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,punchagan/zulip,tommyip/zulip,eeshangarg/zulip,kou/zulip,jackrzhang/zulip,punchagan/zulip,brainwane/zulip,tommyip/zulip,shubhamdhama/zulip,kou/zulip,rishig/zulip,rht/zulip,zulip/zulip,dhcrzf/zulip,showell/zulip,andersk/zulip,jackrzhang/zulip,brainwane/zulip,rishig/zulip,dhcrzf/zulip,timabbott/zulip,zulip/zulip,rishig/zulip,jackrzhang/zulip,kou/zulip,tommyip/zulip,jackrzhang/zulip,showell/zulip,dhcrzf/zulip,eeshangarg/zulip,jackrzhang/zulip,rishig/zulip,zulip/zulip,showell/zulip,punchagan/zulip,zulip/zulip,synicalsyntax/zulip,zulip/zulip,shubhamdhama/zulip,tommyip/zulip,showell/zulip,shubhamdhama/zulip,eeshangarg/zulip,showell/zulip,tommyip/zulip,brainwane/zulip,synicalsyntax/zulip,timabbott/zulip,synicalsyntax/zulip,hackerkid/zulip,punchagan/zulip,andersk/zulip,dhcrzf/zulip,synicalsyntax/zulip,shubhamdhama/zulip,dhcrzf/zulip,punchagan/zulip,eeshangarg/zulip,rht/zulip,rishig/zulip,kou/zulip,synicalsyntax/zulip,jackrzhang/zulip,rishig/zulip,hackerkid/zulip,andersk/zulip,hackerkid/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,tommyip/zulip,shubhamdhama/zulip,tommyip/zulip,shubhamdhama/zulip,rht/zulip,dhcrzf/zulip,timabbott/zulip,brainwane/zulip,timabbott/zulip,synicalsyntax/zulip,timabbott/zulip,dhcrzf/zulip,jackrzhang/zulip,rht/zulip,shubhamdhama/zulip,hackerkid/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,synicalsyntax/zulip,showell/zulip,kou/zulip