It wasn't fully broken but was throwing exceptions anytime you
ran any make command because the errors happened during variable
interpolation.

The playbook the CI job runs trips over the PPA upgrade in
https://github.com/edx/configuration/pull/3470

Update common to pull down the non-ppa python on 16.04

Instead of making the change just for ansible-provision.sh make the
change for all ansible runs.  Most of them don't currently have this
problem right now but I think it makes sense to make them all consistent
and not have to worry about this problem in the future.

When ansible is going over a NAT Gateway or other intermdiate
network devices, the connection can time out if that device has
its own timeout setting for no traffic.  Setting the ServerAliveInterval
will ensure that there is data sent over the wire ever 30 seconds so the
connection does not get closed while running ansible tasks that take
over 5 minutes.

This prevented the -b option to install_stack.sh from working properly.

Now the install happens in the current directory, with logs in a 'logs'
subdirectory.

Other improvements: curl now fails if the Vagrantfile can't be
downloaded, because the RELEASE value is invalid.  Curl also doesn't
print as large a progress bar.  The script fails early if there's no
RELEASE specified.

(cherry picked from commit 66a25250)

Now the install happens in the current directory, with logs in a 'logs'
subdirectory.

Other improvements: curl now fails if the Vagrantfile can't be
downloaded, because the RELEASE value is invalid.  Curl also doesn't
print as large a progress bar.  The script fails early if there's no
RELEASE specified.

Now that it can use AWS tokens for auth, we need to be careful about
just dumping env into logs (and thus into splunk).

Because /var/home_jenkins on our jenkins test containers is mounted from
~/path/to/git/repo/.docker_volumes/jenkins_home you end up with an ssh
socket for ansible which is way past the 108 character unix limit for
filenames of sockets.

If you had a sandbox behind an ELB, this would take the whole sandbox
in/out of the ELB during an ansible run?

Also, this file/path won't exist later on sandboxes which also
source this file when running /edx/bin/update