README.md in reactor-0.14.0 vs README.md in reactor-0.15.0

@@ -140,11 +140,11 @@
 
 <dl>
 <dt>index =></dt>
 <dd>"pets_indexed"</dd>
 </dl>
- 
+
 <dl>
 <dt>show =></dt>
 <dd>"pet_viewed", target: @pet</dd>
 </dl>
 
@@ -165,11 +165,11 @@
   when invalid => "pet_create_failed", errors: @pet.errors, attributes: params[:pet]</dd>
 </dl>
 
 <dl>
 <dt>update =></dt>
-<dd> 
+<dd>
 when valid => "pet_updated", target: @pet, changes: @pet.previous_changes.as_json
 <br />
   when invalid => "pet_update_failed", target: @pet,
                   errors: @pet.errors.as_json, attributes: params[:pet]
 </dd>
@@ -239,9 +239,15 @@
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Add some feature'`)
 4. Push to the branch (`git push origin my-new-feature`)
 5. Create new Pull Request
+
+For testing Reactor itself we use Thoughtbot's [appraisal gem](https://github.com/thoughtbot/appraisal). This lets us test against multiple versions of Sidekiq, Rails, etc. To install appraisal and set up multiple dependencies, do the following:
+
+1. `bundle install` - this will install up-to-date dependencies and appraisal
+2. `appraisal install` - installs dependencies for appraisal groups
+3. `appraisal rake` - runs specs for each appraisal group
 
 ## Open Source by [Hired](https://hired.com/?utm_source=opensource&utm_medium=reactor&utm_campaign=readme)
 
 We are Ruby developers ourselves, and we use all of our open source projects in production. We always encourge forks, pull requests, and issues. Get in touch with the Hired Engineering team at [e-mail]_.