Create configuration directories in /ambassador/ instead of /etc/

This commit modifies the directories being created in the
Dockerfile to be created under /ambassador/ instead of in /etc/.

This lets ambassador to be run as a non-root user with no access
to /etc/.

Fix emissary-ingress#457

ambassador/Dockerfile

@@ -43,12 +43,13 @@ COPY ./ ambassador
 RUN cd ambassador && python3 setup.py --quiet install
 RUN rm -rf ./ambassador
 
-# MKDIR an empty /etc/ambassador-config. You can dump a configmap over this with no
-# trouble, or you can let annotations do the right thing.
-RUN mkdir /etc/ambassador-config
+# MKDIR an empty /application/ambassador-config. You can dump a
+# configmap over this with no trouble, or you can let
+# annotations do the right thing
+RUN mkdir ambassador-config
 
 # COPY in a default config for use with --demo.
-COPY default-config/ /etc/ambassador-demo-config
+COPY default-config/ ambassador-demo-config
 
 # COPY the entrypoint script and make it runnable.
 COPY kubewatch.py .