Add a function to check sequence sync

We've had an issue where sequences have got out of sync with the fields
they are being used by. This manifested as values being generated for
values that already existed in the field in tables, as these are ids
this caused a uniqueness check to fail.

This function will return all of the sequences, the last values they
generated and the maximum value of the field in the table they are used
it. User should then be able to eyeball the out of sync sequences.

This will currently break if any sequence is not in the format
[table]_id_seq for the id field in the given table. Sorry to the person
that finds this commit message and has to fix this. Maybe PostgreSQL
supports regex extraction to pull field and table name.
Remove build test running and tagging
Tag releases in travis

The deployment process is being changed to be more like the other
applications.
Merge pull request #571 from alphagov/deploy-from-deploy

Tag releases in travis rather
Switch Puppetfile git urls to https

We don't allow git traffic out of our infrastructure. Now that puppet is
built there these must be https.
Merge pull request #570 from alphagov/seqs-out-of-sync

Add a function to check sequence sync
Merge pull request #572 from alphagov/deploy-puppet

Switch Puppetfile git urls to https
Add PostgreSQL replication lag to collectd

Create a stored procedure to calculate the number of bytes secondaries
are lagging from the primary. This is only tracked on the primary so it
is only added to the collectd query list there.
Use md5 for postgres monitoring auth

'trust' over tcp is a headache and doesn't seem to work with pgsql.
Use monitoring password
GRANT monitoring SELECT on stagecraft

so that it can get all the data