provisioning: fix up bash profile creation
provisioning: fix up bash profile creation

The base Ubuntu image includes no `.bash_profile`. Creating one will
prevent the existing support scripts in `~/.profile` from loading.

Instead, append our setup code to [whichever script Bash will load
first][bash-startup].

[bash-startup]: https://www.gnu.org/software/bash/manual/html_node/Bash-Startup-Files.html#Bash-Startup-Files

andersk/zulip,timabbott/zulip,andersk/zulip,shubhamdhama/zulip,punchagan/zulip,eeshangarg/zulip,hackerkid/zulip,kou/zulip,synicalsyntax/zulip,zulip/zulip,punchagan/zulip,rht/zulip,eeshangarg/zulip,brainwane/zulip,rht/zulip,hackerkid/zulip,timabbott/zulip,shubhamdhama/zulip,shubhamdhama/zulip,timabbott/zulip,brainwane/zulip,rht/zulip,showell/zulip,eeshangarg/zulip,zulip/zulip,hackerkid/zulip,brainwane/zulip,synicalsyntax/zulip,punchagan/zulip,punchagan/zulip,zulip/zulip,zulip/zulip,andersk/zulip,synicalsyntax/zulip,brainwane/zulip,shubhamdhama/zulip,showell/zulip,eeshangarg/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,eeshangarg/zulip,hackerkid/zulip,rht/zulip,synicalsyntax/zulip,punchagan/zulip,timabbott/zulip,brainwane/zulip,hackerkid/zulip,showell/zulip,andersk/zulip,punchagan/zulip,andersk/zulip,hackerkid/zulip,timabbott/zulip,synicalsyntax/zulip,brainwane/zulip,showell/zulip,andersk/zulip,brainwane/zulip,shubhamdhama/zulip,timabbott/zulip,showell/zulip,showell/zulip,rht/zulip,kou/zulip,kou/zulip,zulip/zulip,kou/zulip,shubhamdhama/zulip,zulip/zulip,rht/zulip,synicalsyntax/zulip,showell/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,zulip/zulip,rht/zulip,andersk/zulip,timabbott/zulip,hackerkid/zulip,shubhamdhama/zulip,synicalsyntax/zulip