Add initiator_id field to EventLog

https://www.agileplannerapp.com/boards/173808/cards/3442

an initiator would represent the user who
initiated the event for a user. useful to
find out who administers a user account.
EventLog optionally records an event initiator

https://www.agileplannerapp.com/boards/173808/cards/3442
Save and show the initiator of a user event

https://www.agileplannerapp.com/boards/173808/cards/3442
Modify integration tests to check event initiator

www.agileplannerapp.com/boards/173808/cards/3442
Merge pull request #236 from alphagov/add-initiator-to-account-access-logs

Add initiator to account access logs
Remove unnecessary negation from suspension logic.

Use `unless` and flip ternary operators to avoid having to think through
too much negation in conditionals; hopefully this makes the logic a bit
clearer.
Merge pull request #237 from alphagov/fix-if-bang

Remove unnecessary negation from suspension logic
Clean up permission updater tests.

Be consistent about how we assert on update calls.  Was previously using
a mixture of webmock, and mocha mocks.  Also remove some unnecessary
detail in some of the stubs.
Improve robustness of permission update worker

Gracefully handle:

* The user no longer existing
* The application no longer existing
* The user no longer having any permissions for the application

Any of these can change between when the job is scheduled, and when it's
actually run.
Improve robustness of the reauth enforcer worker.

It's possible for the application to have been deleted between when the
job was scheduled, and when it's actually run.
Merge pull request #238 from alphagov/update_worker_robustness

Improve robustness of user update workers
Add titles to pages
Change format of title to match other GOV.UK apps

* Switch the order of page title and application name
* Show user name in the title on edit & suspend pages
Show user status on admin edit page
Merge pull request #240 from alphagov/show-user-states

Show user status on admin edit page
Merge pull request #239 from alphagov/add-titles-to-pages

Add titles to pages
Start using admin gem

* Add govuk_admin_template
* Remove jquery-rails, jQuery is provided via gem
Delete bootstrap assets

* All of bootstrap now comes via govuk_admin_template
Remove crown asset

* Crown provided via govuk_admin_template
Switch to using govuk_admin_template layout

* Use nested layouts
* Make application.css SASS friendly, and import gem styles
*