Fix deps_dir sample config

rebar.config.sample

@@ -106,8 +106,8 @@
 
 %% == Dependencies ==
 
-%% Where to put any downloaded dependencies. Default is `deps';
-{deps_dir, ["deps"]}.
+%% Where to put any downloaded dependencies. Default is "deps";
+{deps_dir, "deps"}.
 
 %% What dependencies we have, dependencies can be of 3 forms, an application
 %% name as an atom, eg. mochiweb, a name and a version (from the .app file), or