Fix CI

[deivid-rodriguez]

Summary

Just trying to get the CI green. This PR closes #461.

Details

CI is broken on Rails 6. This PR introduces a number of changes to get CI green again:

• Delay webpacker installation to a point where cucumber-rails is properly setup in the dummy application Gemfile. Otherwise we get warnings like this:

WARNING: Cucumber-rails required outside of env.rb. The rest of loading is being deferred
until env.rb is called. To avoid this warning, move 'gem 'cucumber-rails', require: false'under only group :test in your Gemfile. If already in the :test group, be sure you arespecifying 'require: false'.

and also a hard error about rails generator not finding the webpacker:install task. Honestly I'm not fully sure why it's happening, but we're running webpacker:install later on, so it's unnecessary to include webpacker on the initial dummy application generation.

• Increase aruba's commands timeout, since sassc compilation is very slow, and it comes by default on Rails 6.

• Bump the nodejs version being used to a version compatible with webpacker. Otherwise we get errors like this:

Webpacker requires Node.js >= 8.16.0 and you are using 8.12.0
Please upgrade Node.js https://nodejs.org/en/download/

Motivation and Context

To have a green CI.

How Has This Been Tested?

In CI.

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist:

• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[deivid-rodriguez]

This is ready for a review!

[olleolleolle]

Looks grand, and is now GREEN!

Looks good to me and it's ready to go.

Also: The description is very clear, and explains what was changed and why.

[deivid-rodriguez]

Thanks for your reviews!

I made one last minute change to fix the "Nodejs version is too old" issue. Instead of all the workarounds to upgrade the nodejs version manually, I updated TravisCI configuration to use bionic which seems to provide a high enough version of nodejs by default.

[deivid-rodriguez]

I will merge this after the CI 👍.

[deivid-rodriguez]

Going in!