Fix ssl and specs for 0.18

src/kemal.cr

@@ -10,7 +10,7 @@ module Kemal
     config.add_handler Kemal::RouteHandler::INSTANCE
 
     config.server = HTTP::Server.new(config.host_binding.not_nil!, config.port, config.handlers)
-    config.server.not_nil!.ssl = config.ssl
+    config.server.not_nil!.tls = config.ssl
 
     unless Kemal.config.error_handlers.has_key?(404)
       error 404 do |env|

src/kemal/cli.cr

@@ -45,8 +45,8 @@ module Kemal
         puts "SSL Key Not Found"; exit unless @key_file
         puts "SSL Certificate Not Found"; exit unless @cert_file
         ssl = Kemal::Middleware::SSL.new
-        ssl.set_key_file @key_file.not_nil!.to_slice
-        ssl.set_cert_file @cert_file.not_nil!.to_slice
+        ssl.set_key_file @key_file.not_nil!
+        ssl.set_cert_file @cert_file.not_nil!
         Kemal.config.ssl = ssl.context
       end
     end

src/kemal/config.cr

@@ -3,7 +3,7 @@ module Kemal
     INSTANCE       = Config.new
     HANDLERS       = [] of HTTP::Handler
     ERROR_HANDLERS = {} of Int32 => HTTP::Server::Context -> String
-    @ssl : OpenSSL::SSL::Context?
+    @ssl : OpenSSL::SSL::Context::Server?
     @server : HTTP::Server?
 
     property host_binding, ssl, port, env, public_folder, logging,

src/kemal/middleware/ssl.cr

@@ -3,7 +3,7 @@ module Kemal::Middleware
     getter context
 
     def initialize
-      @context = OpenSSL::SSL::Context.new
+      @context = OpenSSL::SSL::Context::Server.new
     end
 
     def set_key_file(key_file)