fix: Do not leak SemanticLogger settings outside of isolation (#30)

Author: bougyman

examples/echo_endpoint.rb

@@ -16,6 +16,8 @@ def initialize(a_var: 1)
 end
 
 if __FILE__ == $PROGRAM_NAME
+  SemanticLogger.default_level = :info
+  SemanticLogger.add_appender(io: $stdout, formatter: :color)
   EchoService.run(
     nats_url: 'nats://localhost:4222',
     service_opts: {

lib/leopard.rb

@@ -3,7 +3,6 @@
 require 'dry/configurable'
 require 'pathname'
 require 'semantic_logger'
-SemanticLogger.add_appender(io: $stdout, formatter: :color)
 
 class Pathname
   def /(other)