Run tests in Rails 6 project

Also add CONTRIBUTING.md inside .github dir

.github/CONTRIBUTING.md

@@ -0,0 +1,40 @@
+# :pray: Contributing
+
+Thank you for considering or deciding to contribute, this is much appreciated!
+Any kind of bug reports and pull requests are encouraged and welcome on GitHub at
+https://github.com/renderedtext/render_async.
+
+## Installing dependencies
+
+You can install all needed dependencies by running `bin/setup`.
+
+## Running RSpec tests
+
+You can run either `rake spec` or `bundle exec rspec` to run all the RSpec tests
+in the project.
+
+## Running integration tests
+
+There is a simple command `bin/integration-tests` which sets up 2 submodules,
+and runs Cucumber features in them.
+
+There are 2 submodules for render_async. The submodules are Rails 5 and Rails 6
+projects which are located in:
+
+  - `spec/fixtures/rails-5-base-app`, and
+  - `spec/fixtures/rails-6-base-app`.
+
+You can find [Rails 5 base app here](https://github.com/nikolalsvk/rails-5-base-app/tree/render-async),
+and the [Rails 6 base app here](https://github.com/nikolalsvk/rails-6-base-app/tree/render-async).
+
+Each of them have different use cases of render_async defined in `app/views/render_asyncs/_use_cases.html.erb` in their repos.
+All the feature tests are inside `features/render_async.feature` and `features/render_async_jquery.feature` files.
+
+If you are adding one or more feature tests or use cases, make sure to make a
+PR on those repos as well and include them in the PR on the render_async repo.
+
+## Need help
+
+Got any issues or difficulties?
+Join [render_async's Discord channel](https://discord.gg/SPfbeRm)
+and ask questions there. We will try to respond to you as quickly as possible.

.gitmodules

@@ -5,4 +5,4 @@
 [submodule "spec/fixtures/rails-6-base-app"]
 	path = spec/fixtures/rails-6-base-app
 	url = git@github.com:nikolalsvk/rails-6-base-app.git
-	branch = render_async
+	branch = render-async

README.md

@@ -735,17 +735,15 @@ configure other options:
 After checking out the repo, run `bin/setup` to install dependencies. Then, run
 `rake spec` to run the tests. You can also run `bin/console` for an interactive
 prompt that will allow you to experiment. To run integration tests, use
-`bin/integration-tests`.
+`bin/integration-tests`. For more information, check out [CONTRIBUTING](.github/CONTRIBUTING.md) file, please.
 
 Got any questions or comments about development (or anything else)?
 Join [render_async's Discord channel](https://discord.gg/SPfbeRm)
 and let's make `render_async` even better!
 
 ## :pray: Contributing
 
-Thank you for considering or deciding to contribute, this is much appreciated!
-Any kind of bug reports and pull requests are encouraged and welcome on GitHub at
-https://github.com/renderedtext/render_async.
+Check out [CONTRIBUTING](.github/CONTRIBUTING.md) file, please.
 
 Got any issues or difficulties?
 Join [render_async's Discord channel](https://discord.gg/SPfbeRm)

bin/integration-tests

@@ -11,3 +11,10 @@ cd spec/fixtures/rails-5-base-app
 ls
 bundle install
 bundle exec cucumber
+
+cd ../../../spec/fixtures/rails-6-base-app
+ls
+bundle install
+yarn install
+RAILS_ENV=test bundle exec rails webpacker:compile
+bundle exec cucumber