When a Snapshot does not exist, we should raise a `SnapshotMissingException`.
Add also tests for GET/DELETE on non existing repo

Closes #86.

(cherry picked from commit 77ab672)

Unclaimed 23646

 Issue elastic#86

…elastic#86)

Only exec certbot if the certificates do not already exist

* This commit changes the rc.local on both the engageli and ems
instances so that it will only exec certbot when the certificates
do not already exist.  Executing certbot too many times leads to
a rate limit failure, and once created the certs are set to auto
renew on a schedule.  Reference:
https://community.letsencrypt.org/t/is-the-renew-timer-running-on-my-machine-as-it-is-supposed-to/118206

This commit is for https://engageli.atlassian.net/browse/MPC-1496
modified:   instance-files/ems/etc/rc.local
modified:   instance-files/engageli/etc/rc.local

Approved-by: Gideon Avida

With this commit we raise the network timeout for all benchmarks
(regardless whether they have specified client options before or not)
from the previous default value of 60 seconds to 240 seconds. We have
seen some bulk requests fail with a network timeout in recent benchmarks
and hence we bump it so we don't skew results due to timeouts.

Relates elastic#86