Remove user-specific shell customisations
Remove user-specific shell customisations

There are no instances of `bash_aliases` or `.bash.user` defined in
Puppet so it seems that nobody is actually using these.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet