fix activerecord version error when bundling

when doing a `bundle install` or `suspenders <app_name>` there was an error where 2 dependencies relied  on 2 different versions of `activerecord`. If the version spec is vital to an internal workflow, then ignore this, but it has been a persistant error when using suspenders to create rails apps

```sh
Bundler could not find compatible versions for gem "activerecord":
  In Gemfile:
    delayed_job_active_record (>= 4.0.0) ruby depends on
      activerecord (< 4.1, >= 3.0) ruby

    rails (>= 4.0.3) ruby depends on
      activerecord (4.1.0)
```