Upgrade from Webpacker 3 to Shakapacker 7 and React-Rails 3

.gitignore

@@ -19,6 +19,8 @@
 
 /node_modules
 /yarn-error.log
+yarn-debug.log*
+.yarn-integrity
 
 .byebug_history
 /public/packs

.nvmrc

@@ -0,0 +1 @@
+14

Gemfile

@@ -5,19 +5,19 @@ git_source(:github) do |repo_name|
   "https://github.com/#{repo_name}.git"
 end
 
-
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '~> 5.1.4'
+gem "rails", "~> 5.2"
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
 gem 'puma', '~> 4.3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
+# gem 'sassc-rails'
 # Use Uglifier as compressor for JavaScript assets
 gem 'uglifier', '>= 1.3.0'
-# Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
-gem 'webpacker'
+# Transpile app-like JavaScript. Read more: https://github.com/shakacode/shakapacker
+gem 'shakapacker', '7.0.2'
 # See https://github.com/rails/execjs#readme for more supported runtimes
 # gem 'therubyracer', platforms: :ruby
 
@@ -51,4 +51,4 @@ end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
-gem "react-rails"
+gem "react-rails", '= 3.0.0.rc.0'