Do not require legacy rspec formatters

They sometimes cause specs to fail for unknown reasons. Anyway they
are just being used for CI because of RSpec 2 based
CI::Reporter formatter.

Gemfile

@@ -159,7 +159,7 @@ group :test do
   gem 'rspec-activemodel-mocks'
   gem 'rspec-example_disabler', git: "https://github.com/finnlabs/rspec-example_disabler.git"
   # We need the legacy formatters for internal CI scripts
-  gem 'rspec-legacy_formatters'
+  gem 'rspec-legacy_formatters', require: false
   gem 'capybara', '~> 2.4.4'
   gem 'capybara-screenshot', '~> 1.0.4'
   gem 'capybara-select2', github: 'goodwill/capybara-select2'