delete unused gem

Gemfile

@@ -42,7 +42,6 @@ group :development, :test do
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
   gem 'pry'
   gem 'annotate'
-  gem 'letter_opener'
 end
 
 group :development do

Gemfile.lock

@@ -158,10 +158,6 @@ GEM
       activerecord
       kaminari-core (= 1.1.1)
     kaminari-core (1.1.1)
-    launchy (2.4.3)
-      addressable (~> 2.3)
-    letter_opener (1.7.0)
-      launchy (~> 2.2)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
@@ -315,7 +311,6 @@ DEPENDENCIES
   jbuilder
   jquery-rails (= 4.3.1)
   kaminari
-  letter_opener
   listen (>= 3.0.5, < 3.2)
   mysql2 (>= 0.4.4)
   pry

config/environments/development.rb

@@ -62,9 +62,6 @@ Rails.application.configure do
 
   config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
 
-  #Letter Opener
-  config.action_mailer.delivery_method = :letter_opener
-
   #Mailcatcher
   config.action_mailer.delivery_method = :smtp