Add some new files after appraisal install

gemfiles/rails_42.gemfile

@@ -6,6 +6,7 @@ gem "actionpack", "~> 4.2"
 gem "railties", "~> 4.2"
 
 group :development do
+  gem "appraisal", "~> 2.2"
   gem "pry", "~> 0.10.1"
   gem "pry-byebug", "~> 3.2.0"
   gem "sdoc", "~> 0.4.1"

gemfiles/rails_50.gemfile

@@ -6,6 +6,7 @@ gem "actionpack", "~> 5.0"
 gem "railties", "~> 5.0"
 
 group :development do
+  gem "appraisal", "~> 2.2"
   gem "pry", "~> 0.10.1"
   gem "pry-byebug", "~> 3.2.0"
   gem "sdoc", "~> 0.4.1"

gemfiles/rails_51.gemfile

@@ -6,6 +6,7 @@ gem "actionpack", "~> 5.1"
 gem "railties", "~> 5.1"
 
 group :development do
+  gem "appraisal", "~> 2.2"
   gem "pry", "~> 0.10.1"
   gem "pry-byebug", "~> 3.2.0"
   gem "sdoc", "~> 0.4.1"