Remove CommandDefinition class

In preparation for traits support, remove CommandDefinition class
and incorporate the missing functionality into CommandDictionary.

BUG: 25841719
Change-Id: Iead48aa0503e9de6061c4c1588b0b930dd82c8d0
Reviewed-on: https://weave-review.googlesource.com/1680
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/src/weave_unittest.cc b/src/weave_unittest.cc
index 2e41852..dd10cbe 100644
--- a/src/weave_unittest.cc
+++ b/src/weave_unittest.cc
@@ -47,8 +47,11 @@
 
 const char kCommandDefs[] = R"({
   "base": {
-    "reboot": {},
+    "reboot": {
+      "minimalRole": "user"
+    },
     "_shutdown": {
+      "minimalRole": "user",
       "parameters": {},
       "results": {}
     }