Simplify ansible.cfg for general purpose usage

The new ansible.cfg file is copied from matrix-docker-ansible-deploy
and should provide better defaults for general purpose usage.

We've had instances of people wishing to run certain things like `just roles`
using a regular user and to actually run the playbook (`just install-all`) as `root`.
If both of these invocations try to write temporary files to `/tmp/mash*`, they run into a conflict.

It's probably better to avoid writing stuff to `/tmp` by default anyway.

ansible.cfg

@@ -1,29 +1,6 @@
 [defaults]
-forks = 50
-timeout = 86400
-strategy = linear
-ansible_managed = Autogenerated file, do NOT edit manually.
 retry_files_enabled = False
+stdout_callback = yaml
 
-# Paths
-inventory = inventory/hosts
-roles_path = roles
-log_path = /tmp/mash.log
-
-# Remote default
-remote_user = root
-host_key_checking = False
-
-# Display
-display_skipped_hosts = False
-
-# Facts
-gathering = smart
-fact_caching = jsonfile
-fact_caching_connection=/tmp/mash
-
-
-[ssh_connection]
+[connection]
 pipelining = True
-ssh_args = -C -o ControlMaster=auto -o ControlPersist=30m -o PreferredAuthentications=publickey
-control_path = /tmp/mash/ssh-%%h-%%p-%%r