scripts: Remove docker-functions.sh.
scripts: Remove docker-functions.sh.

We've determined that it makes sense to keep this code separate in the
docker-zulip project.

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