Change target directory of the upload task.

The tasks was executed in the release path, but this directory does not exist at the very first deployment,
so the task failed.
The new path is the shared path.
Check if the symfony configuration path exists before uploading the parameters.yml

If the directory does not exist, it is created.
Merge pull request #13 from MartialGeek/fix_parameters.yml_upload

Fix parameters.yml upload