travis: Log the Python version.
travis: Log the Python version.

This allows us to ascertain the Python version under which we ran the
tests.

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