add changelog

changelog/unreleased/unify-config-parsing.md

@@ -0,0 +1,12 @@
+Change: Unify Configuration Parsing
+
+Tags: ocis
+
+- responsibility for config parsing should be on the subcommand
+- if there is a config file in the environment location, env var should take precedence
+- general rule of thumb: the more explicit the config file is that would be picked up. Order from less to more explicit:
+    - config location (/etc/ocis)
+    - environment variable
+    - cli flag
+
+https://github.com/owncloud/ocis/pull/675