Add SimpleCov coverage set up for gRPC ruby
diff --git a/src/ruby/Rakefile b/src/ruby/Rakefile
index afb354e..02af9a8 100755
--- a/src/ruby/Rakefile
+++ b/src/ruby/Rakefile
@@ -26,6 +26,7 @@
   SPEC_SUITES.each do |suite|
     desc "Run all specs in the #{suite[:title]} spec suite"
     RSpec::Core::RakeTask.new(suite[:id]) do |t|
+      ENV['COVERAGE_NAME'] = suite[:id].to_s
       spec_files = []
       suite[:files].each { |f| spec_files += Dir[f] } if suite[:files]