Rename service -> app directory

lib/kamal/cli/base.rb

@@ -101,7 +101,7 @@ module Kamal::Cli
       end
 
       def acquire_lock
-        ensure_service_and_locks_directory
+        ensure_app_and_locks_directory
 
         raise_if_locked do
           say "Acquiring the deploy lock...", :magenta
@@ -174,7 +174,7 @@ module Kamal::Cli
         instance_variable_get("@_invocations").first
       end
 
-      def ensure_service_and_locks_directory
+      def ensure_app_and_locks_directory
         on(KAMAL.hosts) do
           execute(*KAMAL.server.ensure_app_directory)
         end

lib/kamal/cli/lock.rb

@@ -12,7 +12,7 @@ class Kamal::Cli::Lock < Kamal::Cli::Base
   option :message, aliases: "-m", type: :string, desc: "A lock message", required: true
   def acquire
     message = options[:message]
-    ensure_service_and_locks_directory
+    ensure_app_and_locks_directory
 
     raise_if_locked do
       on(KAMAL.primary_host) do