Monkey-patch ruby-git library to speed up branch retrieval.

lib/git/lib.rb

@@ -0,0 +1,17 @@
+module Git
+  class Lib
+    def config_list
+      build_list = lambda do |path|
+        parse_config_list command_lines('config', ['--list'])
+      end
+
+      @config_list ||= begin
+        if @git_dir
+          Dir.chdir(@git_dir, &build_list)
+        else
+          build_list.call
+        end
+      end
+    end
+  end
+end

lib/git_left.rb

@@ -1,3 +1,4 @@
+require_relative "git/lib"
 require_relative "git_left/version"
 require_relative "git_left/branch"
 require_relative "git_left/branch_reporter"