Redirect user to sign_in page after sign_out

Before this change user was redirected to index page which requires
authentication. This caused a 'Signed out successfully' message to be
overriden with 'You need to sign in' message. It was quite confusing
for a user to see 'You need to sign in' message right after signing
out.
Optional argument to set up supported permissions for apps

SupportedPermission objects are required for api client create task
Document how to add permissions to existing apps.
Merge pull request #82 from theodi/supported-permissions-in-app-create-task

Add SupportedPermission support to rake applications:create
make_oauth_work_in_dev more robust

Don't die on the first invalid record; instead report the failure and
continue.
make_oauth_work_in_dev can handle single quoting

These are the two types of quoting in use - single quotes are used in Content
API.
Upgrade ruby to 1.9.3

Bringing this app in line with us wanting to be consistently on 1.9.3 for everything in the stack.
Merge pull request #83 from alphagov/upgrade_ruby_like_a_boss

Upgrade ruby to 1.9.3
Add migration to create edit_fact permission
Update jenkins.sh to abort on error
Remove workaround for rbenv with no .ruby-version file

We now have a .ruby-version file, so this is unnecessary
Initialise then save edit_fact permission

This circumvents protected attributes which prevented the application
association hookup.
Remove unnecessary exit stuff from jenkins.sh

These lines are unnecessary now that we `set -e` at the start.
Merge remote-tracking branch 'origin/add_edit_fact_permission'
use logstasher for logging instead of lograge

lograge throws away a lot of useful information; this change
would bring signon in line with other applications in the stack
initializer to add extra fields to json logs
Merge pull request #87 from alphagov/use-logstasher-instead-of-lograge

use logstasher for logging instead of lograge
Merge pull request #72 from alphagov/explicit_sign_out_message

Redirect user to sign_in page after sign_out
remove the ertp permission in the support app

this permission is no longer needed and has already been removed
from the `support` app
migration idempotence, explicit model definition