Support passing the loader as a block argument.

Author: ioquatix

lib/async/service/configuration.rb

@@ -21,7 +21,12 @@ def self.build(root: Dir.pwd, &block)
 				configuration = self.new
 
 				loader = Loader.new(configuration, root)
-				loader.instance_eval(&block)
+				
+				if block.arity == 0
+					loader.instance_eval(&block)
+				else
+					yield loader
+				end
 
 				return configuration
 			end

releases.md

@@ -4,6 +4,7 @@
 
   - Start health checker earlier in the process. Use `#healthy!` message instead of `#ready!`.
   - Emit prepared and running log messages with durations (e.g. how long it took to transition to prepared and running states).
+  - `Async::Service::Configuration.build{|loader|...}` can now take an argument for more flexible configuration construction.
 
 ## v0.17.0