Only simplecov newer versions

Simplecov has changed ruby version requirements for simplecov-html
apparently. We could define the version of simplecov-html to install
but there's no benefit to running coverage on every version so lets
just install simplecov on newer versions like we do for rubocop

Author: robotdana

Gemfile

@@ -63,10 +63,9 @@ platforms :jruby do
   end
 end
 
-gem 'simplecov', '~> 0.8'
-
-# No need to run rubocop on earlier versions
+# No need to run rubocop & simplecov on earlier versions
 if RUBY_VERSION >= '2.4' && RUBY_ENGINE == 'ruby'
+  gem 'simplecov', '~> 0.8'
   gem "rubocop", "~> 0.52.1"
 end
 

script/rspec_with_simplecov

@@ -24,7 +24,7 @@ begin
   # Simplecov emits some ruby warnings when loaded, so silence them.
   old_verbose, $VERBOSE = $VERBOSE, false
 
-  unless ENV['NO_COVERAGE'] || RUBY_VERSION.to_f < 2.1
+  unless ENV['NO_COVERAGE'] || RUBY_VERSION.to_f < 2.4
     require 'simplecov'
 
     SimpleCov.start do