discovery play fixes

Add script & playbook for reporting on package upgrades

Add some docs, fix some bugs

OPS-1240 Datadog role erroring and causing builds to be marked failed

Add another MIME type for Javascript files.

Enroll test users into testcourses as part of provisioning.

We need test users automatically enrolled into these courses so we
can automate various tests (most immediately, fully-deployed sandboxes
that we run browser testing against.)

See: TE-1128

Erroneous removal in a1509d2e

SEC-79: Install nginx from their ppa

E0d/change name coursediscover

Merge Dogwood changes (so far) into master.

Do the fast checks first and then the slow docker tasks.

Print only the 10 slowest tasks instead of all of them.

add jwt auth settings for edxapp role

Move to using a more recent build for the default devstack.

Max/idempotent mongo 3 0

MA-1955: Add OAuth expiration config.

The dogwood devstack was not compatible with some changes made after dogwood was cut.

DEVOPS-3275 Add theme selector to Jenkins ansible-provision job

Add verbose option to aid debugging failed builds

Previously on this branch, it would attempt to create a superuser and
initialize the replica set after the local host exemption had passed
(once a mongod is started with a keyfile and the replicationSetName
 config file option or --replSet command line argument, you can't create
 users using the localhost exemption anymore ).

This necesarily complicates the logic and requires us to track if we're
initializing a replica set or not (with facts) and to template out
/etc/mongod.conf twice in the initialization case.

Further modifications to the replica set can be run against all the
members and will install mongo on new machines while updating the
replica set on the old machines.  With a further commit on this branch,
we can avoid needlessly restarting mongo on all machines in the cluster.

When we run this on an existing cluster, this stops and starts mongo for
all machines it is run against.  We can't rely on the notify: since that
happens at the end of the play and during initial cluster setup, we need
to restart and pick up the changed config.

Try to stick sensible tags on things

Ensure mongo restarts on the cluster key file change

Add a few playbook notes about common operations

I believe the loops will be easier to debug in the long run.
Essentially, we have a shallow compare loop in check_config_subset
and then a deep compare loop in is_member_subset.

Both functions allow extra information in the config that comes back
from Mongo, since Mongo tracks things like votes: slaveDelay: etc that
may not be reflected in the configuration you pass in.

Do a bit more error checking before asking for the replica set.

The new mongo play wants to be able to run this against an unconfigured
Mongo to find out "Do you even have a replica set?" which this can now
answer (the try/except portion).

In the case where mongo was started without a replSet configured (or
running getCmdLineOpts fails for an OperationFailure reason), we
return a dictionary where status is not included to allow tasks to
detect the failure.  Unfortunately, Ansible doesn't provide an easy way
to log back why you didn't get a replica set doc.

Documentation improvements for this module

Discusses the return values and some examples of checking them.

Simplify get_replset

If the find_one for a replset fails, just return None.
We don't need to worry about getting back a dictionary which contains a
'config' key (presumably this is from an earlier iteration of the code
which called getReplSetStatus which does act like that).

Rather than raising the exception, use the friendly error here.

I assume the raise/module.fail_json double header was leftover cruft
from earlier development.

Make the module work without rs being configured

Initially, this module always tried to find and connect to a primary,
however, during replica set initialization, there is no primary so we
need to fall back to just connecting to the machine specified.

This is detected by catching the replSetGetStatus failure and falling
back to the bare get_client method which refactors the connection.

Remove check for mongo 2.4 since this is the mongo_3_0 role
This was probably carried over from the mongo 2 role. I see no reason
why mongo 2.x and mongo 3 couldn't coexist on the same machine.

Remove old hugepages init script check
This was probably added while we were still iterating on our mongo 3
deployment, but it should no longer be necessary.

Clean up ansible syntax

Don't move the old mongo data dirs
This actually skips for edX because we provision machines that already
have {{mongo_data_dir}} mounted on an external disk.  However, for
non-edX use, this could fail if you turn on WiredTiger since it will
move mmapv1 files into the mongo_data_dir and then mongo will fail to
start because it has been told to use WiredTiger.

Don't make this a serial play
We usually run this on 3 machines, so serial: 3 was equivalent to
ansible's default of "run everything in parallel" but this causes
problems if you ever run it on 4 like we do for prod envs.
In addition, this prevents run_once from working properly, and there are
a number of things we only one to do on one machine (like creating a
superuser).