Tried migrating to postgres, failed, reverted back

Gemfile

@@ -13,10 +13,11 @@ gem 'faker', "~> 1.2.0"
 gem 'will_paginate', '~> 3.0.3'
 gem 'bootstrap-will_paginate'
 gem 'acts_as_follower'
+#gem 'pg'
 
 group :production do
-	gem 'pg'
 	gem 'rails_12factor'
+	gem 'pg'
 end
 
 group :development, :test do

app/models/pin.rb

@@ -10,12 +10,7 @@ class Pin < ActiveRecord::Base
 								size: { less_than: 5.megabytes }
 	belongs_to :user
 			has_attached_file :image,
-			#:storage => :dropbox,
-			#:dropbox_credentials => "#{Rails.root}/config/dropbox.yml",
 			:styles => { :medium => "300x300>", :thumb => "100x100" }
-			#:dropbox_options => {
-      #	:path => proc { |style| "#{style}/#{id}_#{image.original_filename}" }
-    	#}
 
 	def image_remote_url=(url_value)
 		self.image = URI.parse(url_value) unless url_value.blank?

config/database.yml

@@ -22,4 +22,4 @@ production:
   adapter: sqlite3
   database: db/production.sqlite3
   pool: 5
-  timeout: 5000
+  timeout: 5000