Enable sharing to easily share results online

Only share when running within GitHub Actions environment.

Author: etagwerker

Rakefile

@@ -1,5 +1,7 @@
 desc "run benchmark in current ruby"
 task :run_benchmark do
+  ENV['SHARE'] = ENV['GITHUB_ACTIONS'] # only share to http://ips.fastruby.io when running within GitHub Actions env
+
   Dir["code/general/*.rb"].each do |benchmark|
     puts "$ ruby -v #{benchmark}"
     system("ruby", "-v", "-W0", benchmark)