add Plugin#path to make things simpler

lib/heroku/plugin.rb

@@ -32,20 +32,23 @@ def to_s
 			name
 		end
 
+		def path
+			"#{self.class.directory}/#{name}"
+		end
+
 		def install
-			FileUtils.mkdir_p(install_path = "#{self.class.directory}/#{name}")
-			Dir.chdir install_path do
+			FileUtils.mkdir_p(path)
+			Dir.chdir(path) do
 				system("git init > /dev/null 2>&1")
 				if system("git pull --depth 1 #{uri}  > /dev/null 2>&1")
 					FileUtils.rm_rf %w(.git .gitignore)
 				else
-					FileUtils.rm_rf install_path
+					FileUtils.rm_rf path
 				end
 			end
 		end
 
 		def uninstall
-			path = "#{self.class.directory}/#{name}"
 			FileUtils.rm_r path if File.directory?(path)
 		end