Keep exec folders in the repo to help supervisor

Supervisor will fail if required directories do not exist. This can be
rather inconvenient, as we `overwatchDeploy` runs too late to create
them. To avoid this issue, we keep the directories in the repository, so
they'll always exist (assuming execution is started in the Overwatch
root directory, which is usually the case).

docker/README.md

@@ -30,3 +30,7 @@ Since we use supervisor, we use that to handle the logs. Then, we need to select
 Although it appears that it would be convenient to put them in the `dataFolder` directory, this is problematic
 because they will be accessible through the `webApp`. Instead, we put them in the `exec` directory, which is a
 directory dedicated to files generated during execution. It may also contain configuration files, etc.
+
+Note that we explicitly keep empty `logs`, `config` and `sockets` directories inside of the `exec` directory
+in the git repository to ensure that supervisor doesn't fail to execute due missing those directories. It is
+not required to use the directories in the repository, but it certainly is convenient.

exec/.gitignore

@@ -0,0 +1,5 @@
+# We want to ignore everything in these directories
+logs/
+nginx/
+config/
+sockets/