Fix 100% cpu in async examples

This switches from the endless loop to accumulating and joining the
threads.

CHANGELOG.md

@@ -1,6 +1,7 @@
 ### 0.11.2 (Next)
 
 * Your contribution here.
+* [#206](https://github.com/slack-ruby/slack-ruby-client/pull/206): Fix 100% cpu usage in async examples - [@felixbuenemann](https://github.com/felixbuenemann).
 
 ### 0.11.1 (1/23/2017)
 

examples/hi_real_time_async_celluloid/hi.rb

@@ -5,6 +5,7 @@
 $stdout.sync = true
 logger = Logger.new($stdout)
 logger.level = Logger::DEBUG
+threads = []
 
 ENV['SLACK_API_TOKENS'].split.each do |token|
   logger.info "Starting #{token[0..12]} ..."
@@ -28,9 +29,7 @@
     end
   end
 
-  client.start_async
+  threads << client.start_async
 end
 
-loop do
-  Thread.pass
-end
+threads.each(&:join)

examples/hi_real_time_async_eventmachine/hi.rb

@@ -5,6 +5,7 @@
 $stdout.sync = true
 logger = Logger.new($stdout)
 logger.level = Logger::DEBUG
+threads = []
 
 ENV['SLACK_API_TOKENS'].split.each do |token|
   logger.info "Starting #{token[0..12]} ..."
@@ -28,9 +29,7 @@
     end
   end
 
-  client.start_async
+  threads << client.start_async
 end
 
-loop do
-  Thread.pass
-end
+threads.each(&:join)