bumping Plek to 1.0.0

Run  to test
adding govuk_setenv to jenkins
tweaking for govuk_setenv envvar set up
Merge remote branch 'origin/master' into bump-plek

Conflicts:
	Gemfile
	Gemfile.lock
Use latest Plek for it's niceness
Merge pull request #42 from alphagov/bump-plek

Bump plek
Remove redundant govuk_setenv

This broke the build on CI because it doesn't have the command.
Recreate DB with correct environment

It was trying to drop and recreate the development database, but it should do
the test database.