herokuでplay1.2.4を使う

play1.x heroku

dependencies.ymlにversionを設定すれば使える。
1.2.3

# Application dependencies

require:
    - play

1.2.4

# Application dependencies

require:
    - play 1.2.4

pushした時のログ

-----> Heroku receiving push
-----> Play! app detected
-----> Updating Play! version. Previous version was 1.2.3. Updating to 1.2.4...
-----> Installing Play! 1.2.4.....
-----> done
-----> Installing ivysettings.xml..... done
-----> Building Play! application...
       ~        _            _ 
       ~  _ __ | | __ _ _  _| |
       ~ | '_ \| |/ _' | || |_|
       ~ |  __/|_|\____|\__ (_)
       ~ |_|            |__/   
       ~
       ~ play! 1.2.4, http://www.playframework.org
       ~
       1.2.4
       Building Play! application at directory ./
...

楽ちんだな。