Update lint task to run against all files
Update lint task to run against all files

Now that we have resolved all of the linting issues, we can change our
local lint rake task to run against all files.

However, our CI build will still run in the diff mode as documented
here [1].

[1] https://github.com/alphagov/govuk-puppet/blob/master/modules/govuk_jenkins/files/var/lib/jenkins/groovy_scripts/govuk_jenkinslib.groovy#L455-L473

alphagov/content-tagger,alphagov/content-tagger,alphagov/content-tagger