Travis: Remove unnecessary docker services.
Travis: Remove unnecessary docker services.

We aren't using these, and they likely slow down the build.

kou/zulip,rishig/zulip,jackrzhang/zulip,hackerkid/zulip,hackerkid/zulip,shubhamdhama/zulip,mahim97/zulip,dhcrzf/zulip,rishig/zulip,shubhamdhama/zulip,jackrzhang/zulip,Galexrt/zulip,brockwhittaker/zulip,andersk/zulip,tommyip/zulip,kou/zulip,brockwhittaker/zulip,synicalsyntax/zulip,kou/zulip,brockwhittaker/zulip,rishig/zulip,synicalsyntax/zulip,shubhamdhama/zulip,brainwane/zulip,punchagan/zulip,dhcrzf/zulip,shubhamdhama/zulip,andersk/zulip,brainwane/zulip,hackerkid/zulip,rishig/zulip,timabbott/zulip,amanharitsh123/zulip,zulip/zulip,brainwane/zulip,synicalsyntax/zulip,verma-varsha/zulip,showell/zulip,kou/zulip,brainwane/zulip,verma-varsha/zulip,timabbott/zulip,zulip/zulip,punchagan/zulip,Galexrt/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,andersk/zulip,dhcrzf/zulip,mahim97/zulip,eeshangarg/zulip,kou/zulip,dhcrzf/zulip,kou/zulip,synicalsyntax/zulip,mahim97/zulip,amanharitsh123/zulip,dhcrzf/zulip,zulip/zulip,hackerkid/zulip,shubhamdhama/zulip,tommyip/zulip,synicalsyntax/zulip,rishig/zulip,eeshangarg/zulip,showell/zulip,andersk/zulip,dhcrzf/zulip,shubhamdhama/zulip,punchagan/zulip,timabbott/zulip,dhcrzf/zulip,showell/zulip,rht/zulip,tommyip/zulip,punchagan/zulip,brainwane/zulip,mahim97/zulip,amanharitsh123/zulip,rht/zulip,tommyip/zulip,Galexrt/zulip,mahim97/zulip,showell/zulip,eeshangarg/zulip,rht/zulip,shubhamdhama/zulip,punchagan/zulip,zulip/zulip,amanharitsh123/zulip,eeshangarg/zulip,brockwhittaker/zulip,Galexrt/zulip,rht/zulip,timabbott/zulip,timabbott/zulip,Galexrt/zulip,rht/zulip,zulip/zulip,rht/zulip,eeshangarg/zulip,punchagan/zulip,amanharitsh123/zulip,tommyip/zulip,brainwane/zulip,andersk/zulip,brockwhittaker/zulip,rishig/zulip,showell/zulip,andersk/zulip,tommyip/zulip,jackrzhang/zulip,verma-varsha/zulip,synicalsyntax/zulip,andersk/zulip,timabbott/zulip,brainwane/zulip,rishig/zulip,amanharitsh123/zulip,timabbott/zulip,jackrzhang/zulip,hackerkid/zulip,synicalsyntax/zulip,Galexrt/zulip,eeshangarg/zulip,mahim97/zulip,tommyip/zulip,rht/zulip,zulip/zulip,eeshangarg/zulip,brockwhittaker/zulip,verma-varsha/zulip,jackrzhang/zulip,hackerkid/zulip,zulip/zulip,verma-varsha/zulip,Galexrt/zulip,showell/zulip,jackrzhang/zulip,showell/zulip,jackrzhang/zulip,verma-varsha/zulip