Add --all option to pull to update all castles

Abstracted the logic for doing some operation for all castles into
Homesick.inside_each_castle() which takes a block argument. Homesick.list() is
also reimplemented to use this new method, because that's where the logic was
stolen from. The actual updating is also moved to the private method
update_castle() to make pull() shorter.

lib/homesick.rb

@@ -60,14 +60,16 @@ class Homesick < Thor
   end
 
   desc "pull NAME", "Update the specified castle"
-  def pull(name)
-    check_castle_existance(name, "pull")
-
-    inside repos_dir.join(name) do
-      git_pull
-      git_submodule_init
-      git_submodule_update
+  method_option :all, :type => :boolean, :default => false, :required => false, :desc => "Update all cloned castles"
+  def pull(name="")
+    if options[:all]
+      inside_each_castle do |castle|
+        update_castle castle
       end
+    else
+      update_castle name
+    end
+
   end
 
   desc "symlink NAME", "Symlinks all dotfiles from the specified castle"
@@ -107,13 +109,10 @@ class Homesick < Thor
 
   desc "list", "List cloned castles"
   def list
-    Pathname.glob("#{repos_dir}/**/*/.git") do |git_dir|
-      castle = git_dir.dirname
-      Dir.chdir castle do # so we can call git config from the right contxt
+    inside_each_castle do |castle|
       say_status castle.relative_path_from(repos_dir), `git config remote.origin.url`.chomp, :cyan
     end
   end
-  end
 
   desc "generate PATH", "generate a homesick-ready git repo at PATH"
   def generate(castle)
@@ -158,4 +157,21 @@ class Homesick < Thor
     end
   end
 
+  def inside_each_castle(&block)
+    Pathname.glob("#{repos_dir}/**/*/.git") do |git_dir|
+      castle = git_dir.dirname
+      Dir.chdir castle do # so we can call git config from the right contxt
+        yield castle
+      end
+    end
+  end
+
+  def update_castle(castle)
+    check_castle_existance(castle, "pull")
+    inside repos_dir.join(castle) do
+      git_pull
+      git_submodule_init
+      git_submodule_update
+    end
+  end
 end