HTTP::Handler is not a class anymore

src/kemal/base_log_handler.cr

@@ -1,6 +1,8 @@
 module Kemal
   # All loggers must inherit from `Kemal::BaseLogHandler`.
-  abstract class Kemal::BaseLogHandler < HTTP::Handler
+  abstract class Kemal::BaseLogHandler
+    include HTTP::Handler
+
     abstract def call(context)
     abstract def write(message)
   end

src/kemal/common_exception_handler.cr

@@ -1,6 +1,7 @@
 module Kemal
   # Kemal::CommonExceptionHandler handles all the exceptions including 404, custom errors and 500.
-  class CommonExceptionHandler < HTTP::Handler
+  class CommonExceptionHandler
+    include HTTP::Handler
     INSTANCE = new
 
     def call(context)

src/kemal/filter_handler.cr

@@ -1,7 +1,8 @@
 module Kemal
   # Kemal::FilterHandler handle all code that should be evaluated before and after
   # every request
-  class FilterHandler < HTTP::Handler
+  class FilterHandler
+    include HTTP::Handler
     INSTANCE = new
 
     # This middleware is lazily instantiated and added to the handlers as soon as a call to `after_X` or `before_X` is made.

src/kemal/handler.cr

@@ -1,4 +1,5 @@
-class Kemal::Handler < HTTP::Handler
+class Kemal::Handler
+  include HTTP::Handler
   @@only_routes_tree = Radix::Tree(String).new
   @@exclude_routes_tree = Radix::Tree(String).new
 

src/kemal/init_handler.cr

@@ -1,7 +1,8 @@
 module Kemal
   # Kemal::InitHandler is the first handler thus initializes the context with default values such as
   # Content-Type, X-Powered-By.
-  class InitHandler < HTTP::Handler
+  class InitHandler
+    include HTTP::Handler
     INSTANCE = new
 
     def call(context)

src/kemal/route_handler.cr

@@ -3,7 +3,8 @@ require "radix"
 module Kemal
   # Kemal::RouteHandler is the main handler which handles all the HTTP requests. Routing, parsing, rendering e.g
   # are done in this handler.
-  class RouteHandler < HTTP::Handler
+  class RouteHandler
+    include HTTP::Handler
     INSTANCE = new
 
     property tree