[1-0-stable] Devise Security Upgrade ( 1.4.8 > 1.5.3 )

Upgrading Devise in the 1.0.x branch in regard to the 28th Jan security notice

##### Background

Due to heavy customisation, we are locked in on v1.0.x for one app and have been using the 1-0-stable branch for recent Rails security updates, this patch is in keeping with the last few commits.

##### Note on tests

Tests are __failing__ in this commit, however the failing tests exist prior. The auth gem is green and our own testsuite for an application using this ref is green and currently undergoing QA.