Upgrade gds-sso to 9.2.5

- This fixes a problem where we were seeing duplicate users created in
  Preview when we signed in to Transition, because Transition's
  database is synced to preview each night but Signon's isn't. The SSO
  gem wasn't recognising us as already having a user, but this bug was
  fixed in this later version of the gem.
- All our tests still pass, so this looks good.
Merge pull request #308 from alphagov/update_gds-sso

Upgrade gds-sso to 9.2.5
Upgrade admin gem to 0.1.0

* Fix broken footer html
* Fix visited link styles on bootstrap components
* Get environment indicator styles
Add custom Transition favicons
Use gem's "link-inherit"

* Replaces the more specific glossary link style
Merge pull request #305 from alphagov/environment-indicator

Show environment indicator
Avoid counting things for summary

* Use of #any? was triggering a count query
* Use of .to_a will make sure that #any? happens on an array
* Avoids one COUNT per summary category for a 30% speed boost
Eager load hosts and mappings
Fix a tags performance regression

* Switching to taggings for eager loading created a table
  scan on 250K row table taggings when indexing Mapping.
  Create an index to mitigate the effects of this.
* See https://github.com/alphagov/transition/commit/514f017ac2ecee7022faa603ee5c48e892d0d425
Merge pull request #307 from alphagov/performance-of-hits

Performance of hits pt1
Only validate New URL in whitelist for redirects

Other validations of New URL are only done if the type is a redirect. This
means that if you typed in something invalid for New URL and then changed the
type to Archive, it won't reject the change you actually wanted and complain
about the value of a field which we have hidden from view with JavaScript.
Merge pull request #312 from alphagov/only_validate_in_whitelist_if_redirect

Only validate New URL in whitelist for redirects
Don't redisplay mappings progress messages

Disable caching on responses which include feedback on progress to avoid
confusing users who hit the back button.

We don't want to disable it on every page because:
* this would unnecessarily slow down the user experience
* values in forms would no longer be retained when a user hits the back button
Use only instead of except to limit routes used

It looks as though we were accidentally allowing the destroy route
to exist for whitelisted hosts, because we were excluding delete
instead of destroy. This fixes that issue.
Merge pull request #314 from alphagov/only_routes

Use only instead of except to limit routes used
Merge pull request #313 from alphagov/dont_cache_pages_with_mapping_progress_message

Don't redisplay mappings progress messages
Add a count of all the whitelist entries in the table
Merge pull request #315 from alphagov/whitelist_entry_count

Add a count of all the whitelist entries in the table
Fix collation for some columns

These columns were created whilst their tables had the utf8_general_ci
collation, and had preserved this setting on the columns even after we
had manually altered the collation at the table level. The migration here
alters the text and varchar columns on those tables to be consistent with
the other InnoDB tables.

The history of how we got into this state is in this commit message:

    https://github.gds/gds/puppet/commit/310eb6370c893a849a5a0944e4243a031ff93cba

That change was deployed a few weeks ago, and since then the
whitelisted_hosts table has been correctly created with utf8_unicode_ci,
so collation for new tables should be fine in future. The following tables
had been created with utf8_general_ci and were manually altered to utf8_unicode_ci:

- mappings_batch_entries
- mappings_batches
- organisations_sites
- sessions

Those tables now have the correct table-level collation, but text and
varchar columns in those tables still had the wrong collation at the
column level. A new varchar column created on one of those tables since
the table collation was fixed does have the correct collation (type on
mappings_batches).

Collation in itself doesn't make any difference for these four tables:
we don't sort by any of their text columns and even if we did, most of
them store ASCII-only text which would be sorted identically between the
two collations in question anyway. We only want this fixed so that we can
have a predictable and consistent db/structure.sql, and the update to that
file here should put us back into a world of happiness and consistency.
Merge pull request #316 from alphagov/fix_collation_woes

Fix collation for some columns