merged branch jdespatis/master (PR #545)

This PR was submitted for the master branch but it was merged into the 2.1 branch instead (closes #545).

Discussion
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Remove +x mode on file app/logs/.gitkeep

Mode on app/cache/.gitkeep is 100644, same mode should be applied to app/logs/.gitkeep

Further more, afaik, .gitkeep doesn't aim to be a shell script

Commits
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89a18a4 Remove +x mode on file