Remove rollbar gem dependency

We already support Errbit and Airbrake as error monitoring services.
Since some people might not want to setup Errbit and might prefer
Rollbar over Airbrake, we're referencing it in the custom gemfile.

Gemfile

@@ -47,7 +47,6 @@ gem "recipient_interceptor", "~> 0.3.0"
 gem "redcarpet", "~> 3.5.1"
 gem "responders", "~> 3.0.1"
 gem "rinku", "~> 2.0.6", require: "rails_rinku"
-gem "rollbar", "~> 3.2.0"
 gem "sassc-rails", "~> 2.1.2"
 gem "savon", "~> 2.12.1"
 gem "sitemap_generator", "~> 6.1.2"

Gemfile.lock

@@ -521,7 +521,6 @@ GEM
     retriable (3.1.2)
     rexml (3.2.5)
     rinku (2.0.6)
-    rollbar (3.2.0)
     rspec-core (3.10.1)
       rspec-support (~> 3.10.0)
     rspec-expectations (3.10.1)
@@ -765,7 +764,6 @@ DEPENDENCIES
   redcarpet (~> 3.5.1)
   responders (~> 3.0.1)
   rinku (~> 2.0.6)
-  rollbar (~> 3.2.0)
   rspec-rails (~> 5.0)
   rubocop (~> 1.18.4)
   rubocop-performance (~> 1.11.4)

Gemfile_custom

@@ -21,6 +21,9 @@
 # application errors and performance
 # gem "sentry-ruby", "insert_gem_version_here"
 
+# Rollbar is an external service which helps you monitor the application errors
+# gem "rollbar", "insert_gem_version_here"
+
 ###### Other gems ######
 #
 # Add your custom gem dependencies here

config/initializers/rollbar.rb

@@ -1,53 +0,0 @@
-require "rollbar/rails"
-Rollbar.configure do |config|
-  # Without configuration, Rollbar is enabled in all environments.
-  # To disable in specific environments, set config.enabled=false.
-
-  config.access_token = Rails.application.secrets.rollbar_server_token
-
-  # Here we'll disable all environments except 'staging', 'preproduction' and 'production':
-  if Rails.env.staging? || Rails.env.preproduction? || Rails.env.production?
-    config.enabled = Rails.application.secrets.rollbar_server_token.present?
-  else
-    config.enabled = false
-  end
-
-  # By default, Rollbar will try to call the `current_user` controller method
-  # to fetch the logged-in user object, and then call that object's `id`,
-  # `username`, and `email` methods to fetch those properties. To customize:
-  # config.person_method = "my_current_user"
-  # config.person_id_method = "my_id"
-  # config.person_username_method = "my_username"
-  # config.person_email_method = "my_email"
-
-  # If you want to attach custom data to all exception and message reports,
-  # provide a lambda like the following. It should return a hash.
-  # config.custom_data_method = lambda { {:some_key => "some_value" } }
-
-  # Add exception class names to the exception_level_filters hash to
-  # change the level that exception is reported at. Note that if an exception
-  # has already been reported and logged the level will need to be changed
-  # via the rollbar interface.
-  # Valid levels: 'critical', 'error', 'warning', 'info', 'debug', 'ignore'
-  # 'ignore' will cause the exception to not be reported at all.
-  # config.exception_level_filters.merge!('MyCriticalException' => 'critical')
-  #
-  # You can also specify a callable, which will be called with the exception instance.
-  # config.exception_level_filters.merge!('MyCriticalException' => lambda { |e| 'critical' })
-
-  # Enable asynchronous reporting (uses girl_friday or Threading if girl_friday
-  # is not installed)
-  # config.use_async = true
-  # Supply your own async handler:
-  # config.async_handler = Proc.new { |payload|
-  #  Thread.new { Rollbar.process_from_async_handler(payload) }
-  # }
-
-  # Enable asynchronous reporting (using sucker_punch)
-  # config.use_sucker_punch
-
-  # Enable delayed reporting (using Sidekiq)
-  # config.use_sidekiq
-  # You can supply custom Sidekiq options:
-  # config.use_sidekiq 'queue' => 'my_queue'
-end

config/secrets.yml.example

@@ -44,7 +44,6 @@ staging:
   errbit_project_key: ""
   errbit_project_id: 1
   errbit_self_hosted_ssl: false
-  rollbar_server_token: ""
   http_basic_username: ""
   http_basic_password: ""
   managers_url: ""
@@ -71,7 +70,6 @@ preproduction:
   errbit_project_key: ""
   errbit_project_id: 1
   errbit_self_hosted_ssl: false
-  rollbar_server_token: ""
   http_basic_username: ""
   http_basic_password: ""
   managers_url: ""
@@ -103,7 +101,6 @@ production:
   errbit_project_key: ""
   errbit_project_id: 1
   errbit_self_hosted_ssl: false
-  rollbar_server_token: ""
   http_basic_username: ""
   http_basic_password: ""
   managers_url: ""