updates for heroku deployment

Gemfile

@@ -6,7 +6,14 @@ ruby '2.6.5'
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.2.3'
 # Use sqlite3 as the database for Active Record
-gem 'sqlite3'
+#gem 'sqlite3'
+group :development, :test do
+  gem 'sqlite3'
+end
+
+group :production do
+  gem 'pg'
+end
 # Use Puma as the app server
 gem 'puma', '~> 3.11'
 # Use SCSS for stylesheets

Gemfile.lock

@@ -103,6 +103,7 @@ GEM
     nio4r (2.5.2)
     nokogiri (1.10.8)
       mini_portile2 (~> 2.4.0)
+    pg (1.2.2)
     public_suffix (4.0.3)
     puma (3.12.2)
     rack (2.2.2)
@@ -197,6 +198,7 @@ DEPENDENCIES
   coffee-rails (~> 4.2)
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
+  pg
   puma (~> 3.11)
   rails (~> 5.2.3)
   sass-rails (~> 5.0)

config/routes.rb

@@ -1,4 +1,5 @@
 Rails.application.routes.draw do
+  root 'cars#index'
   resources :cars
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end