test: use different rspec versions

Appraisals

@@ -23,6 +23,10 @@ end
 
 appraise 'rails-6-1' do
   gem 'rails', '~> 6.1.0'
+  group :test do
+    gem 'rspec', '~> 3.4'
+    gem 'rspec-rails', '~> 3.4'
+  end
   platforms :ruby do
     gem 'sqlite3', '~> 1.4'
   end
@@ -35,6 +39,10 @@ end
 
 appraise 'rails-7-0' do
   gem 'rails', '~> 7.0.0'
+  group :test do
+    gem 'rspec', '~> 3.4'
+    gem 'rspec-rails', '~> 3.4'
+  end
   platforms :ruby do
     gem 'sqlite3', '~> 1.4'
   end

gemfiles/rails_5_2.gemfile

@@ -4,6 +4,10 @@ source "http://rubygems.org"
 
 gem "rails", "~> 5.2.0"
 
+platforms :ruby do
+  gem "sqlite3", "~> 1.6"
+end
+
 platforms :jruby do
   gem "activerecord-jdbc-adapter", "~> 52.0"
   gem "activerecord-jdbcpostgresql-adapter", "~> 52.0"

gemfiles/rails_6_1.gemfile

@@ -4,6 +4,11 @@ source "http://rubygems.org"
 
 gem "rails", "~> 6.1.0"
 
+group :test do
+  gem "rspec", "~> 3.4"
+  gem "rspec-rails", "~> 3.4"
+end
+
 platforms :ruby do
   gem "sqlite3", "~> 1.4"
 end

gemfiles/rails_7_0.gemfile

@@ -4,6 +4,11 @@ source "http://rubygems.org"
 
 gem "rails", "~> 7.0.0"
 
+group :test do
+  gem "rspec", "~> 3.4"
+  gem "rspec-rails", "~> 3.4"
+end
+
 platforms :ruby do
   gem "sqlite3", "~> 1.4"
 end