Gemfile and gem lock

Gemfile

@@ -9,10 +9,10 @@ end
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.1.0'
 # Use mysql as the database for Active Record
-#gem 'mysql2', '>= 0.3.18', '< 0.5'
+gem 'mysql2', '>= 0.3.18', '< 0.5'
 
 #Use PosgreSQL
-gem 'pg'
+#gem 'pg'
 
 # redis server for cable
 gem 'redis', '~> 3.0'

Gemfile.lock

@@ -114,11 +114,11 @@ GEM
     mini_portile2 (2.1.0)
     minitest (5.10.2)
     multi_json (1.12.1)
+    mysql2 (0.4.6)
     nio4r (2.1.0)
     nokogiri (1.7.2)
       mini_portile2 (~> 2.1.0)
     pdf-core (0.7.0)
-    pg (0.20.0)
     prawn (2.2.2)
       pdf-core (~> 0.7.0)
       ttfunk (~> 1.5)
@@ -251,7 +251,7 @@ DEPENDENCIES
   jquery-rails
   kaminari!
   listen (~> 3.0.5)
-  pg
+  mysql2 (>= 0.3.18, < 0.5)
   prawn
   prawn-table
   puma (~> 3.0)