Delete useless test file

 - rc_test.json was simulating the configuration file in
   home user the file, to test value, on development purpose

rc_test.json

@@ -1,12 +0,0 @@
-{
-    "progs" : [
-        "task",
-        "echo test",
-        "task +rdv",
-        "vim"
-    ],
-
-    "settings" : [
-        "Todo"
-    ]
-}