Fixed tests for os file system not to use a fake runner

Signed-off-by: Damien Le Berrigaud <damien@pivotallabs.com>
Added support for running complex commands in runner
 * This allows changing working directory
 * This allows settings env variables

Signed-off-by: Damien Le Berrigaud <damien@pivotallabs.com>
Refactor compile to correctly run the packaging command

Signed-off-by: Damien Le Berrigaud <damien@pivotallabs.com>
Refactored compile package action to delegate to a compiler object

Signed-off-by: Damien Le Berrigaud <damien@pivotallabs.com>