dropzonejs-rails | Spice your Rails apps with some Dropzone sugar | File Upload library

Followed this simple hello world and created app https://iridakos.com/tutorials/2013/11/24/saying-hello-world-with-ruby-on-rails.html . Then trying to add file upload using dropzonejs-rails

I am trying to migrate from Rails 4.2 to Rails 5.0 (running on ruby 2.3) (see plan here https://stackoverflow.com/a/38443616/7374136)

The plan is to:

1. Update the rails gem and all dependencies.
2. Run tests (covering almost our whole code base) for depreciations and fix them.
3. Run rake rails:update to update Rails
4. Adapt the configuration, application classes, breaking changes, ...

Nevertheless, I am blocked at the first step already, updating the rails gem and dependencies. gem 'rails', '4.2.5' -> gem 'rails', '~> 5.0' running: bundle update rails.

I faced multiple dependencies issues, which I fixed by looking for any dependencies that ultimately require rails to be less than 5, and see if those can be updated. Running:

I am trying to deploy the ruby application to elastic beanstalk and I am having an error as follows;

I am trying to deploy my ROR application to heroku, but getting this error constantly. I downgraded my Ruby version to 2.3.0. This is what I have on my Gemfile.lock

RUBY VERSION ruby 2.3.0p0

BUNDLED WITH

But I still get the below error and also heroku always trying to use the Ruby version 2.4.4 and bundler 1.15.2 even though my lock file has the different version.

remote: -----> Using Ruby version: ruby-2.4.4 remote: -----> Installing dependencies using bundler 1.15.2

An error occurred while installing json (1.8.1), and Bundler cannot continue. remote: Make sure that gem install json -v '1.8.1' succeeds before bundling. remote:
remote: In Gemfile: remote: dropzonejs-rails was resolved to 0.7.0, which depends on remote: rails was resolved to 4.1.7, which depends on remote: actionmailer was resolved to 4.1.7, which depends on remote: actionpack was resolved to 4.1.7, which depends on remote: actionview was resolved to 4.1.7, which depends on remote: activesupport was resolved to 4.1.7, which depends on remote: json

Any help on this would be appreciated. Thanks in advance.