Fixes Composer installation issue

Fixes an issue discovered at CakeFest 2013 where composer installs the plugin as `CakephpGerman` and it should be `Gearman`.

NOTE: I can't test how composer uses this version of the file on my local machine but this *should* fix the issue according to the composer docs. See: https://github.com/composer/installers#custom-install-names
Merge pull request #1 from alecho/master

Fixes Composer installation issue